Lead Ruby Developer

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We’re Hiring: Lead Ruby Developer (12+ Years Experience)

Location: Chicago, IL (On-site – 5 Days/Week)

Duration: 12+ Months Contract

We are looking for a highly experienced Lead Ruby Developer to join a high-impact engineering team working on large-scale, high-performance systems. This role is ideal for someone who has deep expertise in Ruby internals and has successfully scaled enterprise-grade applications.

Key Responsibilities & Expertise:

We are seeking a hands-on engineer with deep mastery in:

Ruby & Rails Internals

• 12+ years of Ruby development experience
• Strong understanding of MRI internals (GIL, memory model, object allocation)
• Ruby GC (mark & sweep, generational GC) expertise
• Rails internals (ActiveRecord, middleware stack, Arel)
• Performance tuning: N+1 queries, memory leaks, slow query optimization

Concurrency & Performance Engineering

• Multi-threaded Ruby (Puma, Sidekiq tuning)
• Thread pools, Fibers, Ractors
• Async frameworks (Falcon, Async gem)
• Proven ability to scale Rails apps to 10K+ RPS and millions of transactions/day
• Low-latency optimization (sub-50ms API response under load)

Distributed Systems & Architecture

• Event-driven systems (Kafka / RabbitMQ)
• CQRS, Event Sourcing, Saga patterns
• Schema design (Avro / JSON Schema) & evolution
• Strong understanding of eventual consistency & distributed transactions
• Idempotent API design

Data & Storage

• PostgreSQL (indexing, query tuning, locking, replication)
• Redis (pub/sub, distributed locks, caching strategies)
• Database sharding and read replicas

Background Processing

• Deep Sidekiq expertise (queues, retries, dead jobs, middleware)
• Redis contention debugging
• Job idempotency design

Cloud & DevOps

• AWS (EKS, RDS, SQS, Lambda)
• Docker & Kubernetes
• CI/CD pipelines (GitHub Actions / Jenkins)
• Observability: Prometheus, Grafana, ELK/OpenSearch

Security & APIs

• OAuth2 / JWT authentication
• Secure API design (rate limiting, mTLS, encryption)
• PCI-DSS exposure preferred

Bonus Experience

• High-frequency trading / payment systems / crypto platforms
• JRuby / TruffleRuby
• GraphQL & gRPC
• Fraud detection & real-time risk engines

If you or someone in your network fits this profile, please email at [email protected] or DM me with your updated resume.

Pay: $70.00 - $75.00 per hour

Work Location: In person