Case Study

Fedoras - Catalog Import for Continuous Inventory Accuracy

We supported a multifaceted program across several key projects, using Agile principles to drive impressive results.

Industry

Solution

Platform

Case Study

Fedoras

Catalog Import for Shopify B2B Products for Multi-Location Retailers
MLVeda

Fedoras - Catalog Import for Continuous Inventory Accuracy

Introduction

Fedoras.com, a U.S.–based accessories retailer with rapidly expanding B2B and DTC channels on Shopify Plus, was hitting a hard ceiling: every new product drop or supplier restock required merchandisers to juggle error‑prone CSV files, wait hours for bulk inventory updates to finish, and then chase down mismatched SKUs across multiple warehouse locations. Internal logs showed that manual flat‑file imports consumed ~20 operations hours per month and triggered a 3 % SKU‑mismatch rate, translating into reducing stock‑outs, canceled orders, and lost revenue during peak seasons.

The pain intensified as Fedoras opened regional fulfillment nodes to improve two‑day delivery across North America. Each new location multiplied the complexity of inventory synchronisation—yet Shopify’s native admin allowed only one inventory upload at a time. What the brand needed was geo‑aware, high‑throughput inventory syncing that scaled with its multi‑location strategy while keeping inventory data “five‑nines” accurate.

MLVeda delivered an embedded, API‑driven solution that enables faster inventory turnaround through bulk inventory updates, turning supplier CSVs into validated, location‑aware updates in under 30 minutes—setting the foundation for a broader Shopify B2B accelerator now being rolled out across our B2B client base. This automated solution ensures inventory replenishment automation, minimizing stock discrepancies and allowing Fedoras.com to keep inventory levels synchronized in real time.

We supported a multifaceted program across several key projects, using Agile principles to drive impressive results.

Industry

Solution

Platform

Client
Fedoras
Industry
Online Hat Store
Solutions
Shopify B2B Products
Project Timeline
4 Weeks

Challenges – The Hidden Friction Behind Inventory Accuracy

Fedoras.com had modernized its front‑end on Shopify Plus, yet its inventory engine still ran on nightly CSV uploads. Every supplier restock forced merchandisers to reconcile mismatched columns, babysit long‑running imports, and then patch stock errors across five U.S. and Canadian distribution centers—a process that consumed ~20 operations hours per month and drove a 3 % SKU‑mismatch rate. As order volumes grew, flat-file workflow latency and lack of real-time inventory updates hindered revenue growth, delayed product drops.

Data Table
Challange Under‑the‑Hood Technical Root Cause Quantified / Operational Impact
Single‑inventory limitation in Shopify Admin Admin import endpoint handles one file per job; no native multi‑inventory batching or location mapping 4–5 uploads per vendor, per location—>20 ops hrs/month lost to repetitive work
Schema drift and vendor‑specific column orders Inconsistent headers (e.g., Qty vs Quantity, missing Location ID) passed straight to Shopify without validation 3 % SKU mismatch rate, causing oversells during peak promotions
No idempotent update logic Shopify’s native import rewrote entire stock levels; partial or stale rows corrupted live inventory Daily “import‑then‑fix” loop, inflating after‑hours support workload
Multi‑location catalog import bottleneck CSVs lacked a location dimension; mapping to Location IDs required manual API calls post‑import Regional back‑orders and higher last‑mile shipping costs
Escalating vendor count (>8 by Q1 2025) Each supplier introduced its own CSV template, cut‑off times, and validation rules Integration maintenance consumed >30 % of engineering backlog

Collectively, these bottlenecks throttled Fedoras.com’s ability to scale its Shopify Plus B2B program across North America. Fixing them would require a location‑aware, schema‑validated import pipeline capable of turning flat files into “five‑nines” inventory accuracy—without adding headcount or slowing product launches

Solution – API-Driven, Location-Aware Catalog Import

To erase flat-file friction, MLVeda engineered an embedded Catalog Import application that lives inside the Shopify Plus Admin, validates supplier CSVs in real time, and posts inventory updates to every U.S. and Canadian distribution center in a single, fault-tolerant run. The design principle: treat every import like code—tested, versioned, and idempotent.

  1. Drag-and-Drop Upload UI
    • Polaris-based React component lets merchandisers choose a vendor, select up to 20 CSVs at once, and map each file to one or more Shopify Location IDs—no spreadsheet gymnastics.
  2. Schema-Aware Validation Layer
    • JSON-schema engine confirms header order, data types, and mandatory fields (SKU, Location ID, On-Hand Qty, Cost).
    • Row-level errors surface instantly; files that fail validation never reach Shopify.
  3. Serverless Import Orchestrator for Bulk Inventory Updates
    • AWS Lambda parses validated CSVs and pushes them to GraphQL Bulk Operations, achieving ~4,000 mutations per minute without hitting rate limits.
    • AWS SQS queues and de-duplicates jobs, ensuring idempotent updates even if the same SKU appears in multiple files.
  4. Incremental & Absolute Stock Logic
    • Merchandisers pick “Replace” or “Delta” mode. Replace wipes and rewrites counts; Delta applies net changes—solving the stale-file issue that once caused phantom oversells.
  5. Real-Time Progress & Observability
    • Web-socket progress bar shows rows processed, success/failure counts, and ETA.
    • Structured logs stream to Datadog; error thresholds trigger Slack alerts and automatic Lambda retries.
  6. Multi-Vendor Extensibility
    • New suppliers plug in via a YAML config: header map, delimiter, and unique validation rules—no code merge required.
    • Architecture already sized for sub-minute webhook feeds, future-proofing the move from batch to real time.

This API-driven pipeline cuts import cycle time from hours to <30 minutes, slashes SKU mismatches to <0.2 %, and scales effortlessly as Fedoras.com adds new suppliers or distribution hubs across North America.

Key Components - Architecture Built for Scale and Accuracy

The Catalog Import solution for Fedoras.com was designed with modularity, fault tolerance, and extensibility as first principles. Each component played a critical role in transforming flat-file chaos into a reliable, location-aware inventory pipeline that fits seamlessly into Shopify’s B2B ecosystem.

Data Table
Component Purpose Technical Implementation Why It Matters
Polaris-based Upload UI Enable merchandisers to drag-and-drop multiple CSVs mapped to vendors and locations Built with React using Shopify Polaris; supports batch upload with vendor/location tagging Lowers training burden and prevents mismatches by pushing schema enforcement upstream
Schema Validation Engine Enforce structural integrity before files touch Shopify JSON schema + regex validation with live error feedback at row level Blocks “bad data in” scenarios; eliminates 90% of downstream fire drills
Serverless Import Orchestrator Manage high-throughput ingestion without hitting API rate limits AWS Lambda functions connected to SQS queues; writes to Shopify via GraphQL Bulk Operations Fault-tolerant, scalable, and easily extensible for future file formats or feed types
Serverless Import Orchestrator Manage high-throughput ingestion without hitting API rate limits AWS Lambda functions connected to SQS queues; writes to Shopify via GraphQL Bulk Operations Fault-tolerant, scalable, and easily extensible for future file formats or feed types
Idempotent Stock Handler Prevent double-counting or inventory loss during re-uploads Dual-mode: “Replace All” and “Apply Delta” logic; SKU-level deduplication on import Enables safe reprocessing and supports partial file corrections without data corruption
Progress & Alert Dashboard Give ops teams real-time visibility into job status Web-socket live progress, success/failure counters, Slack integration, and retry alerts Improves confidence and allows time-sensitive inventory drops to proceed on schedule
Vendor Config Layer Add new suppliers without writing code Config-as-code for vendor schema, delimiters, and import thresholds Future-proofs the platform as supplier count scales; zero developer involvement for onboarding

Together, these components deliver a purpose-built inventory management layer on top of Shopify that eliminates SKU mismatches, reduces human error, and dramatically shortens the time from vendor file to live inventory.

Implementation – Rapid, Low‑Risk Rollout in Four Controlled Waves

The implementation approach emphasized speed to first value, data integrity, and repeatable scale. We treated the Catalog Import capability as a mini‑platform build rather than a one‑off script—establishing clear quality gates, observability, and extensibility from day one.

1

Discovery & Specification (Day 1)

Data Table
Objective Activities Deliverables Success Criteria
Baseline current import workflow Shadow 1 live import; capture file variations across top vendors; enumerate location IDs Current‑state process map; vendor schema inventory All mandatory columns & edge cases documented
Define target schema & modes Consolidate required / optional fields; decide Replace vs Delta semantics; version initial JSON schema v1 JSON schema + sample “golden” CSV Stakeholder sign‑off (<24h turnaround)
Risk & dependency scan Identify API limits, peak upload windows, rollback needs Risk register + mitigation plan No unmitigated “High” risks

Key Decisions:
Adopt a versioned JSON schema (v1.0) with forward‑compatible optional fields; introduce Delta mode to avoid stale full‑file overwrites; enforce location mapping at upload (not post‑processing).

2

 Build & Internal QA (Days 2–11)

Data Table
Stream Work Items Tooling / Patterns Quality Gate
Front-End (Polaris UI) Multi‑file drag‑and‑drop, vendor + location tagging, schema pre‑check React + Polaris; client-side schema probe 100% required fields flagged pre‑submit
Validation Layer JSON schema service, header normalization, row-level error collector Node/TypeScript, AJV (schema), custom regex ≥95% negative test cases blocked
Stock Logic Delta calculator (previous qty cache), Replace path, conflict resolution Dynamo “last known” table + conditional writes All race conditions resolved in parallel test
Observability & Alerts Structured logging, progress polling endpoint, Slack webhook thresholds CloudWatch logs + metric filters P95 import latency trend visible
Security & Access Shopify App OAuth scopes least‑privileged; signed upload URLs Scoped API keys, secrets in Parameter Store Pen test checklist cleared
Orchestrator & Queues Lambda handler, SQS fan‑out, Bulk Operation builder, retry/idempotency keys AWS Lambda, SQS, Dynamo (job state) Zero duplicate SKU updates in test harness

Test Coverage:

80%+ logic branches; synthetic load test (10 simultaneous imports, 50k total rows) under targeted runtime budget (<30 min end‑to‑end).

3

UAT & Controlled Pilot (Days 12–16)

Data Table
Step Description Data Set Exit Criteria
Golden Path Import Clean vendor file → single location 2k rows <5 min ingest, zero errors
Multi-File Batch 5 CSVs, mixed vendors, overlapping SKUs (Delta + Replace modes) 8k rows No stock divergence vs expected snapshot
Error Injection Missing columns, bad data types, negative qty, duplicate header 1.5k rows 100% correctly quarantined; human-readable error list
Performance Soak Repeat multi-file batch every hour (peak simulation) 24 runs No backlog growth; memory footprint stable
Ops Training Walkthrough + runbook; simulate rollback scenario Live sandbox Ops can execute import + rollback without dev support


Slack alerts verified (start, 50%, completion, anomaly). Latency / error dashboards approved by ops and merchandising leads.

4

 Production Launch & Hypercare (Days 17–20)

Data Table
Window Focus Metrics Monitored Intervention Triggers
Go-Live Day First real vendor batch (Replace mode) Import duration, failed rows, API throttles Any failed row >0.5% → halt subsequent imports
Days 2–5 Incremental vendor onboarding; Delta mode validation Delta accuracy vs baseline inventory snapshot Delta variance >0.25% → force full Replace
Days 6–10 Stability & tuning; alert threshold recalibration P95 row processing time P95 > target (50 ms/row) → scale concurrency
Post-Day 10 Transition to BAU + backlog grooming Monthly ops hours saved, SKU mismatch rate Deviation from target KPIs for 2 consecutive runs

Rollback plan:
Toggle feature flag to freeze new imports; replay last “known good” Dynamo snapshot with Replace mode. RTO (Recovery Time Objective) < 15 minutes.


Implementation Principles (Embedded for Ongoing Scale)

Data Table
Principle Applied Design Choice Resulting Benefit
Shift Left on Data Quality Client-side + server-side schema checks Defects blocked before API consumption
Idempotency Everywhere Deterministic job IDs + SKU + location composite keys Safe replays; no double-counting
Observable by Default Structured logs + percent completion API Faster incident triage; proactive alerts
Config over Code Vendor onboarding via YAML Zero dev cycle for new suppliers
Mode Explicitness User-selectable Replace vs Delta Eliminates silent partial overwrites
Performance Guardrails Concurrency tuned to stay below GraphQL limits Predictable runtimes under load


KPI Baselines Set During Implementation

Data Table
KPI Baseline (Pre-Project) Target (Defined During Build) Early Actual (First 2 Weeks)
Full Catalog Import Time ~4 hours manual effort <30 min end-to-end 24–27 min
SKU Mismatch Rate 3.0% <0.5% 0.18%
Ops Hours / Month (Imports) 20 hrs <3 hrs 2.5 hrs


5
6

Results – 2 Weeks In

Within the first two weeks of deployment, Fedoras.com saw clear improvements across every operational KPI tied to bulk catalog updates, inventory accuracy and inventory management. These changes also led to significant operational cost reduction, with a decrease in manual data handling and the labor-intensive nature of previous inventory management workflows, particularly benefiting Shopify Plus B2B retailers operating across multi-location North American fulfillment centers.

Quantitative Outcomes

Data Table
KPI Pre‑Implementation Post‑Implementation Change (%)
Full Catalog Import Time ~4 hrs manual effort 24–27 minutes automated ↓ ~90%
SKU Mismatch Rate 3.0% 0.18% ↓ 94%
Ops FTE Hours on Imports (Monthly) 20+ hrs ~2.5 hrs ↓ 88%
Rollback Readiness (Time to Recovery) Undefined <15 minutes (tested) -
First-Time Import Success Rate ~60% 99.8% ↑ 66 pp
Time to Launch New Product Line (Inventory-ready) ~2 days <6 hours ↓ ~75%


Operational & Strategic Wins

Data Table
Outcome Description
Higher SKU confidence across DCs Improved synchronization eliminated back-orders due to phantom inventory in regional hubs
Shift-left on QA 90%+ of data issues now caught pre-ingest via schema validation, reducing downstream firefighting
Faster supplier onboarding New vendors can be added via config file in <1 hour, vs. 2–3 days of spreadsheet back-and-forth
B2B readiness at scale Fedoras can now batch upload location-mapped inventories from multiple vendors in parallel, a capability critical for growth in B2B segments

Best Practices & Key Takeaways

Fedoras.com’s success with automated catalog import wasn’t accidental. It was the result of targeted architectural choices, early validation of assumptions, and a relentless focus on operational edge cases. These practices are broadly relevant to Shopify Plus merchants managing high-SKU inventories across multiple warehouses or suppliers.

 

1. Validate Before You Import

Why it matters: Flat files from vendors are inherently untrustworthy.
What worked: JSON-schema validation on the client and server side with row-level error messages.
Takeaway: Catching errors before ingestion saved 90% of downstream fire drills and preserved the integrity of inventory records.

 

2. Design for Idempotency from Day One

Why it matters: Catalog import will fail. What matters is how gracefully they recover.
What worked: Every job, file, and SKU-location update used a deterministic key structure to ensure safe retries.
Takeaway: Idempotency eliminates the fear of reprocessing and supports automated rollback strategies.

 

3. Treat Inventories as Multi-Dimensional Objects

Why it matters: Shopify’s native tools assume a single inventory, single location model. Real B2B environments rarely work that way.
What worked: Upload UI required location mapping per file; processing logic routed SKUs to the correct Shopify location IDs.
Takeaway: Inventory must be location-aware and vendor-scoped to enable regional fulfillment and cross-border compliance.

 

4. Make Progress Observable, Not Just Executable

Why it matters: Ops teams lose trust when they’re left guessing.
What worked: Live dashboard with percent complete, error count, and Slack alerts at key thresholds.
Takeaway: Visibility builds confidence and reduces the need for manual spot-checks before product drops.

 

5. Use Config, Not Code, for Extensibility in Automated Inventory Management

Why it matters: Every new vendor should not be a dev ticket.
What worked: Vendor templates were defined via YAML: header mappings, column types, import thresholds.
Takeaway: Treating onboarding as a configuration task empowered non-technical users and cut cycle time from days to minutes.

 

6. Give Merchandising Control Without Engineering Bottlenecks

Why it matters: Merch teams need autonomy to launch and update without risking inventory accuracy.
What worked: Embedded UI in Shopify Admin with no external login or middleware console.
Takeaway: Putting control where users already work shortens ramp-up time and minimizes process errors.

 

7. Plan for What’s Next (Not Just What’s Broken)

Why it matters: Solving today’s pain shouldn’t create tomorrow’s rigidity.
What worked: The architecture supports both bulk CSV uploads and webhook-based real-time updates.
Takeaway: Build now, but don’t block evolution—especially as Shopify B2B expands its native Functions and Credit APIs.

 

Conclusion – From Flat Files to a Scalable Inventory Ops Platform

Fedoras.com’s catalog import challenge was never just about files—it was about unlocking operational agility at scale. By replacing fragmented spreadsheets and manual corrections with a fault-tolerant, location-aware pipeline embedded directly in the Shopify Plus Admin, the brand now manages inventory with near real-time accuracy across five distribution centers and eight active vendors.

The project eliminated hours of repetitive effort, surfaced data issues before they reached production, and gave the merchandising team the confidence to launch new product lines without fear of stockouts or silent failures. More importantly, it laid the foundation for B2B growth: batch uploading location-specific inventories, onboarding vendors in hours not days, and preparing for the eventual rollout of Shopify-native credit, payment, and fulfillment capabilities.

What Comes Next — MLVeda’s B2B Accelerator

This implementation now powers the core of MLVeda’s Shopify B2B Accelerator, a modular solution stack designed to address key platform gaps for manufacturers, distributors, and high-SKU retailers. Future roadmap items include:

  • Store Credit & Conditional Payment Terms
    Logic to handle customer-specific credit limits, store credit balances, and dynamic payment methods at checkout (using Shopify Functions and Payment Extensions as they mature)
  • Split Shipments & Location-Aware Pricing
    Inventories will support price and stock differentiation by fulfillment center—especially useful for brands operating in both U.S. and Canada
  • Webhook-Based Real-Time Updates
    Transitioning from CSV batch uploads to continuous inventory syncing using supplier system webhooks or middleware integrations
  • Admin-Controlled Access Rules
    Allowing team-based permissions around inventory ingestion, rollback, and audit trail visibility


Fedoras.com’s success story is not an endpoint—it’s a reference architecture for how the Shopify B2B ecosystem can evolve beyond native limitations and toward fully automated, multi-location, multi-vendor operations.

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