Evaluating a contract developer is different from evaluating a permanent hire. You have less time, the relationship is more transactional, and you can't rely on cultural fit indicators. You need a fast, signal-rich technical assessment that tells you quickly whether the engineer can do the specific work you need.
What You're Actually Testing
For contract roles, the four things that matter most â in order:
- Specific stack depth â not "knows Java" but "has production Spring Boot 3 + Kubernetes experience at scale"
- Problem-solving approach â how they think, not just what they know
- Async communication â critical for remote work; often tested inadvertently during the hiring process itself
- Self-direction â can they pick up a well-scoped task and execute without micromanagement?
The 3-Stage Evaluation That Works
Stage 1: The Async Technical Screen (45 min)
Give them a small, real problem â ideally anonymised from your actual codebase. Not LeetCode. Not a puzzle. A real engineering problem: "Here's a slow query, diagnose it and propose a fix" or "Here's a poorly designed API endpoint, what would you change and why?"
Async delivery (written response or short video walkthrough) also tests communication skill simultaneously.
Stage 2: Live System Design (45 min)
A verbal design session relevant to your domain. "Design a rate-limiting service for our API" or "How would you structure the data model for this feature?" You're evaluating: do they ask good clarifying questions, do they think about edge cases, do they talk through trade-offs or just give you one answer.
Stage 3: Code Review Exercise (30 min)
Give them a real PR to review. What issues do they catch? What do they miss? How do they frame feedback? This is the fastest signal on whether someone will contribute positively to your team's quality bar.
Red Flags in Technical Interviews
- Answers that are technically correct but don't consider operational concerns (observability, failure modes, scalability)
- No questions back â engineers who don't ask questions usually don't understand the problem well enough
- Impressive CV that doesn't hold up under 5 minutes of specific questions about what they actually built
- Slow response during the async stage â a reliable preview of how they'll communicate on the job
Using a Staffing Partner's Vetting
A good staffing partner runs this process before you see any CVs. When Greatex shortlists 3 profiles, each has already passed a technical coding test, a system design interview, and a communication round. Your evaluation becomes a 30-minute domain-specific conversation, not a 3-stage process from scratch.
Pre-Screened Engineers Ready for Your Technical Round
Every Greatex profile has passed 4 rounds of screening. 72-hour shortlist.
See Profiles →