Work Summary at Quantexa

Author: Usman Kayani (usmankayani@quantexa.com)
GitHub: q-usmankayani
Export Date: 2 January 2026
Total Tickets: 481 | Total PRs: 379

Executive Summary

This document summarises my comprehensive work at Quantexa across Data Engineering, DataOps, and Developer Experience domains. The work spans multiple repositories including internal-data-feeds, data-packs, quantexa-platform, standard-parsers, and supporting infrastructure.

Key Achievements & Impact

1. Self-Service Batch Operations Platform (Epic DO-135)

Status: In Progress | Role: Architect & Lead Developer

Designed and building a comprehensive self-service platform for ETL → Batch Resolver → Post-BR quality checks, enabling R&D teams to safely request and run jobs through Slack with approval workflows.

Key Deliverables:

  • Slack → Airflow Bridge (DO-140) - Built working prototype with:
    • Slack bot processing workflow messages with approval/rejection flows
    • Run cards with GCS paths, DAG URLs, and ES index lookup commands
    • kubectl-based trigger engine (fully working)
    • Airflow REST API client (ready for future integration)
    • Interactive approval flows with threaded updates
  • Dynamic BR Config Generation (DO-119) - Multi-datasource ochre.conf generation
  • Resolver Config Version Control (DO-136) - Immutable config snapshots
  • Run Cards (DO-138) - Surfaced configs for debugging
  • Input Validation (DO-141) - Slack workflow UX improvements

Target KPIs:

  • Median request-to-run time < 2 minutes after approval
  • ≥ 95% successful self-service runs
  • ≥ 70% adoption within 60 days
  • 50% reduction in debug time

2. DataOps & Developer Experience (Epic DO-194)

AI Tooling Rollout (DO-198, DO-199) ✅ Done

  • Created comprehensive claude.md for internal-data-feeds repository
  • 9 commits, 1,436 additions establishing AI coding guidelines
  • Rolled out AI tooling strategy across the team

DevEx Enhancements (DO-388) - Investigation spike for improvements

DataOps Guidelines (DO-394) - Publishing standardised operational guidelines

3. ETL Infrastructure & Airflow Development

Dataproc Logger Redesign (DF-1955) ✅ Done

Major refactoring to reduce Cloud Logging API overuse:

  • Lightweight path for successful jobs (≤2 API calls)
  • Verbose diagnostic logging only for failures
  • Rate limiting with exponential backoff
  • Log Explorer URL generation

Airflow Compatibility & Migration

  • DF-1942 - Fixed Airflow code for new deployment compatibility
  • DF-1943 - Fixed airflow-deploy pipeline post-upgrade
  • DF-1684 - Upgraded Airflow ETL from 1.x to 2.7
  • DF-1690 - DAG health checks and reserialize after promotion
  • DF-1692 - Version mismatch resolution for nightly pipelines

Dynamic DAG Helpers Refactoring (DO-208)

  • Modular architecture with utility classes
  • Type hints and improved error handling
  • Pre-commit standards compliance (black, isort, flake8)

4. Incident Response & Production Stability

Elasticsearch Load Issues

  • DO-221 - OS incremental ETL prod failure (circuit_breaking_exception)
  • DO-260 - OS Incremental Elastic Client Timeout
  • DO-256 - OC Incremental Failure investigation
  • Multiple PRs for ES stability and resolver nodes configuration

Dataproc Executor Failures (DO-234)

Comprehensive investigation of intermittent failures:

  • Exit code -100/-143 analysis
  • YARN container eviction diagnosis
  • Preemptible VM reclamation patterns
  • Enhanced Flexibility Mode (EFM) configuration

OpenSanctions ETL Failures (DF-1953) ✅ Done

  • Expanded schema validation whitelist for new entity types
  • Fixed validation threshold breaches (0.0721% → 0.1805%)

Airflow Scheduler Issues

  • DO-230 - CICD deployments failing due to scheduler pod unavailability
  • DF-1924 - DAG reserialization causing scheduler overload

5. Batch Resolver & ETL Pipeline Work

One-off Batch Resolve (DF-1904) ✅ Done

  • D&B + Dow Jones batch resolve for internal projects
  • Parser version coordination and output location management

Parser Version Testing Support

  • DO-25, DO-46 - Parsers 4.2/4.3 baseline ETL, BR, and EQ Tooling
  • DO-57, DO-59 - 4.3.2-B and 2.7_1.3 Data Packs ETL
  • DO-111 - 3.1 and 4.2.3-LEGACY ETL reruns
  • DO-97 - Testing branch migration to new Airflow version

Batch Resolve Pattern Migration (DF-2008) ✅ Done

  • Moved to new batch-resolve pattern across datasources

6. Data Source Specific Work

D&B (Dun & Bradstreet)

  • DF-1835 - countriesToProcess filtering bug investigation
  • DF-1830 - Documentation updates (ISO3 → ISO2)
  • Country subsetting validation fixes

Orbis

  • DF-1718 - Parquet ETL date parsing fixes
  • DF-1701 - Year ingest fixes
  • Validation threshold configuration
  • mega-n2-big-executor cluster configurations

OpenSanctions

  • Schema whitelist expansion for new entity types
  • Validation threshold management

Dow Jones

  • BufferHolder issue investigation (mega docs)
  • Associates array size optimization

GRID

  • DF-1711 - Regression fixes

WorldCheck

  • DF-1803 - Regression testing changes
  • Diff test fixes

7. Infrastructure & Pipeline Improvements

VM and Job Labels (DF-1997/DO-318) ✅ Done

  • Added VM labels for better resource tracking
  • Job labelling for monitoring and cost attribution

Cluster Configuration

  • Boot size consistency with Airflow
  • Max YARN attempts optimization for elastic jobs
  • Spark compression codec additions
  • Max app attempts dynamic configuration

Jenkins Pipeline Improvements

  • Shadow JARs to GCS (DO-188)
  • Release pipeline version bumping fixes
  • Airflow deployment switching to new pipelines

8. Documentation & Onboarding

  • DO-397 - DataOps Onboarding Guide (In Progress)
  • DO-398 - Review/Auto-Cleanup Deprecated DAGs
  • DF-1655 - Updated Orbis ETL metrics documentation
  • Confluence documentation for workflow UX

9. Code Quality & Technical Debt

Consolidate Script Improvements (DF-1617)

  • Performance improvements for ConsolidateScript
  • Generic improved consolidate script implementation

Delete File Schema Unification (DF-1653)

  • Made Document ID deletions optional
  • Unified delete file schema handling

Gradle Configuration Cache (DO-196)

  • Investigation for standard-parsers optimization

Repository Contributions

internal-data-feeds (Primary)

  • Airflow DAG development and maintenance
  • Dynamic DAG helpers and operators
  • Jenkins pipeline management
  • Configuration management (ochre.conf, batch.json)

data-packs

  • Parser-specific ETL fixes
  • Validation utilities
  • Schema updates for Orbis, D&B, WorldCheck, GRID

quantexa-platform

  • ConsolidateScript improvements
  • Incremental ETL schema handling
  • Core ETL framework contributions

standard-parsers

  • Gradle configuration cache investigation

quantexa-documentation

  • ETL metrics updates
  • Technical documentation

Technical Skills Demonstrated

Languages & Frameworks:

  • Python (Airflow DAGs, Slack bots, automation scripts)
  • Scala (ETL pipelines, Spark jobs)
  • Groovy (Jenkins pipelines, CI/CD)
  • HOCON/JSON (Configuration management)

Infrastructure:

  • Google Cloud Platform (Dataproc, GCS, IAP, Cloud Logging)
  • Kubernetes (kubectl, pod management)
  • Airflow 1.x → 2.7 (DAG development, operators, sensors)
  • Elasticsearch (indexing, cluster management)

Tools & Practices:

  • Jenkins CI/CD pipelines
  • Slack API integration
  • Git workflow management
  • Jira project management

Epics Owned/Created

Epic Title Status
DO-135 Self-Service Batch Operations (DataOps) To Do
DO-193 DataOps Support Epic In Progress
DO-194 DevProd Epic In Progress
DO-238 Incidents - Dev ETL Active
DO-240 Incidents - Prod ETL Active
DO-241 Automated Incremental ETL Framework Preparing
DO-374 Package Airflow Modules as a Product Preparing
DO-377 Self-Service Trigger DAGs Closed
DO-379 Standardized PE Airflow Alignment Done

Sprint Participation

Active participation across multiple sprints:

  • Prism Sprint 1 & 2 (Dec 2025 - Jan 2026)
  • EQ Sprints 0-8 (Jun 2025 - Nov 2025)
  • Data Feeds Sprints (Mar 2025 - Dec 2025)

Key PRs by Category

Merged PRs (Selected Highlights)

PR Repository Title Impact
#1189 internal-data-feeds Claude.md +1,436 lines
#1076 internal-data-feeds Dataproc logger redesign Performance
#1142 internal-data-feeds Batch resolve pattern Architecture
#973 internal-data-feeds Airflow 2.7 compatibility Migration
#1010 internal-data-feeds OpenSanctions schema fix Bug fix
#889 internal-data-feeds One-off batch resolve Feature
#23265 quantexa-platform Delete file schema unification Core improvement

Open PRs

PR Repository Title Status
#1197 internal-data-feeds Slack-Airflow bridge prototype In Review
#1609 standard-parsers Gradle config cache Open
#922 internal-data-feeds Dynamic DAG helpers refactor Open

Summary Statistics

  • Total Story Points Delivered: ~50+ (estimated from completed tickets)
  • Repositories Contributed To: 8+
  • Incidents Resolved: 15+
  • Features Delivered: 20+
  • Documentation Updates: 10+

This document was auto-generated from Jira and GitHub data exports.