API Decomposition & Performance Enhancement
Budget: $5,000 – $10,000 USD
Project: API Refactor & Performance Optimization (FastAPI / Postgres / Async Architecture)
We’re seeking a Senior Backend Engineer or small elite team to transform a legacy monolithic endpoint into a modern, high-performance, event-driven API layer. This is not a simple port—it’s a surgical re-architecture focused on responsiveness, scalability, and clean contracts between frontend and backend.
Context
We’ve migrated a .NET monolith to Python + FastAPI. The current system works but suffers from latency caused by an “all-in-one” endpoint. The goal is to decompose this endpoint, introduce asynchronous orchestration, and implement database- and API-level optimizations to achieve sub-second response times.
Key Deliverables
Redesign existing endpoint into modular, parallelizable endpoints (OpenAPI-driven, p95 ≤ 800 ms).
Implement async job orchestration using Celery/RQ with Redis, WebSocket streaming for long-running tasks.
Optimize Postgres performance (EXPLAIN/ANALYZE, composite + geo indexes, caching, materialized views).
Add observability & CI perf gates (OpenTelemetry + Prometheus + GitHub Actions).
Produce short Architecture Decision Records (ADRs) and parity tests vs legacy .NET endpoints.
Tech Stack
Python 3.11 | FastAPI | SQLAlchemy | Alembic | Redis | Celery/RQ | Postgres | Docker | AWS ECS/Fargate
Ideal Candidate
5 + years backend experience with async APIs and high-throughput systems.
Proven results reducing API latency > 70%.
Excellent communicator—able to collaborate with frontend and DevOps.
Comfortable owning from profiling → refactor → deploy → measure.
(Bonus) Background in geospatial queries, campaign-style recommendation systems, or startup-speed delivery.
Timeline
Target completion: 6–8 weeks
Phase 1 (2 weeks): Analysis + design + PoC for one decomposed vertical.
Phase 2 (4–6 weeks): Full implementation, optimization, and instrumentation rollout.
Success = measurable performance gains, production-ready code, and clear documentation.
Show us your best FastAPI refactor or async orchestration project—links or repos preferred.
We’re seeking a Senior Backend Engineer or small elite team to transform a legacy monolithic endpoint into a modern, high-performance, event-driven API layer. This is not a simple port—it’s a surgical re-architecture focused on responsiveness, scalability, and clean contracts between frontend and backend.
Context
We’ve migrated a .NET monolith to Python + FastAPI. The current system works but suffers from latency caused by an “all-in-one” endpoint. The goal is to decompose this endpoint, introduce asynchronous orchestration, and implement database- and API-level optimizations to achieve sub-second response times.
Key Deliverables
Redesign existing endpoint into modular, parallelizable endpoints (OpenAPI-driven, p95 ≤ 800 ms).
Implement async job orchestration using Celery/RQ with Redis, WebSocket streaming for long-running tasks.
Optimize Postgres performance (EXPLAIN/ANALYZE, composite + geo indexes, caching, materialized views).
Add observability & CI perf gates (OpenTelemetry + Prometheus + GitHub Actions).
Produce short Architecture Decision Records (ADRs) and parity tests vs legacy .NET endpoints.
Tech Stack
Python 3.11 | FastAPI | SQLAlchemy | Alembic | Redis | Celery/RQ | Postgres | Docker | AWS ECS/Fargate
Ideal Candidate
5 + years backend experience with async APIs and high-throughput systems.
Proven results reducing API latency > 70%.
Excellent communicator—able to collaborate with frontend and DevOps.
Comfortable owning from profiling → refactor → deploy → measure.
(Bonus) Background in geospatial queries, campaign-style recommendation systems, or startup-speed delivery.
Timeline
Target completion: 6–8 weeks
Phase 1 (2 weeks): Analysis + design + PoC for one decomposed vertical.
Phase 2 (4–6 weeks): Full implementation, optimization, and instrumentation rollout.
Success = measurable performance gains, production-ready code, and clear documentation.
Show us your best FastAPI refactor or async orchestration project—links or repos preferred.
Related categories:
Business, Accounting, Human Resources & Legal
Python
PostgreSQL
Redis
Elasticsearch
Docker
API Development
FastAPI