Contract Backend Developer Jobs in Illinois (NOW HIRING)

Candidates who are primarily looking for task-based development work may not be the right fit; this role requires technical ownership before, during, and after implementation.

We are seeking a hands-on Lead Backend Engineer / Technical Lead to help design, evolve, and extend the backend and middleware systems that support our trading and market data infrastructure.

This is not a ticket-only development role. We are looking for someone who can take business needs, operational problems, and high-level requirements and turn them into clear technical designs, implementation plans, acceptance criteria, and production-ready code.

You will work on real trading systems involving market data ingestion, exchange connectivity, clearing and regulatory workflows, pre-trade and post-trade processing, and internal services that must be correct, fast, observable, and resilient.

The right person is a strong Java engineer who can also think at the system level: understand tradeoffs, design service boundaries, challenge incomplete requirements, define edge cases, guide other developers, and own technical outcomes from concept through production.

What You’ll Own

• Translate business and operational requirements into technical designs, implementation plans, and acceptance criteria
• Design backend services and middleware components for trading, market data, clearing, regulatory, and post-trade workflows
• Lead technical design discussions and make practical architecture decisions across services, databases, APIs, and integrations
• Write high-quality code for low-latency, high-reliability systems
• Define service contracts, data flows, error handling, observability, retry behavior, and failure modes
• Design and optimize SQL schemas, queries, stored procedures, and data integrity rules
• Integrate with exchanges, clearinghouses, regulatory systems, internal platforms, and third-party services
• Review code and designs from other engineers with a focus on correctness, maintainability, performance, and operational risk
• Identify architectural gaps, technical debt, production risks, and opportunities to simplify or harden the system
• Partner with business stakeholders, product owners, operations, QA, and other developers to clarify requirements before implementation begins
• Support production systems when needed and use incidents as feedback for better architecture and design
• Help establish engineering standards, design patterns, documentation practices, and development best practices

What We’re Looking For

• 8+ years of professional software engineering experience, with significant backend Java experience
• Strong Java expertise, including concurrency, collections, memory behavior, performance tuning, and production debugging
• Proven experience designing systems, not just implementing assigned tickets
• Experience writing or contributing to technical design documents, architecture proposals, implementation plans, or RFCs
• Ability to define acceptance criteria, edge cases, failure scenarios, and testable technical requirements
• Experience with trading systems, market data platforms, financial infrastructure, or other high-throughput/low-latency systems
• Strong understanding of distributed systems, messaging, service-oriented architecture, APIs, and data consistency
• Strong SQL experience, including schema design, query tuning, indexing, data modeling, and transactional integrity
• Ability to communicate clearly with both technical and non-technical stakeholders
• Strong judgment around when to build, refactor, simplify, harden, or defer
• Comfort working in regulated or compliance-driven environments

Preferred Experience

• Exchange connectivity, FIX protocol, proprietary exchange APIs, or market data feeds
• Clearing, settlement, allocation, give-up, regulatory, or post-trade workflows
• Pre-trade risk, order routing, execution workflows, or brokerage/trading operations
• Linux-based server environments
• Message queues, streaming systems, event-driven architecture, or real-time processing
• Observability tools, logging standards, metrics, alerting, and production diagnostics
• Cloud or hybrid infrastructure experience
• Experience mentoring developers or serving as a technical lead on complex backend systems

What Success Looks Like

Within the first 30 days, you will understand the core architecture, major data flows, production risks, and current development process.

Within 60 days, you will be contributing production code, reviewing designs, improving acceptance criteria, and helping shape implementation plans before development starts.

Within 90 days, you will be leading design for meaningful backend changes, identifying architectural risks, and helping the team move from ticket execution to better technical ownership.

This Role Is a Fit If You

• Ask “what problem are we solving?” before jumping into code
• Can turn ambiguity into a clear technical plan
• Care about correctness, latency, resilience, and maintainability
• Know how to make practical architecture decisions without over-engineering
• Are comfortable challenging unclear requirements respectfully
• Can still write serious production code while operating at a higher design level
• Want ownership of systems, not just a queue of tickets