How We Built This List and Our Ranking Criteria
The AI engineering hiring market has a supply problem. There are not enough experienced LLM product engineers, ML engineers with production deployment experience, and AI systems architects to meet current UK demand. The platforms that surface the best candidates are those with genuine AI community relationships, vetting processes that go beyond CV screening, and reach into the specific communities where AI engineers are active. We evaluated platforms on five criteria. AI talent depth: does the platform have a meaningful pool of engineers who have shipped production AI products (not just academic ML or data science)? Time-to-candidate: how quickly can you reach qualified candidates who are available? This matters enormously when you have a 90-day hiring target. Vetting quality: is the vetting more than a coding test? Production AI engineering requires system design thinking, not just algorithm problem-solving. Cost structure: job board annual fees, recruiter placement fees (typically 15 to 25% of first-year salary for permanent roles), and contractor platform margins vary significantly. Contractor capability: for companies that want to hire contractors as a bridge or as a primary model, does the platform support this?
The Full Ranked List: Pros, Cons, and Best For
1. Otta (now Welcome to the Jungle). The best UK startup job platform for tech talent. Strong AI engineer presence. Culture and team-focused profiles appeal to the AI engineering community. Best for: startups hiring AI engineers who care about mission and culture alongside compensation. Limitation: less suited to contract hiring. 2. LinkedIn. The largest professional network. AI engineer search by skill, open to work status, and connection-of-connection reach is unmatched. InMail to AI engineers often works when cold outreach elsewhere does not. Best for: any company with a recruiter or founder willing to invest time in personalised outreach. Limitation: very high noise-to-signal ratio; requires strong filtering. 3. Turing. Vetted remote AI engineer network. Strong screening process that goes beyond CV. Day rates are competitive. Best for: companies comfortable with remote or distributed AI engineers. Limitation: US-centric in candidate pool despite UK availability. 4. Hired. Tech-focused job marketplace where candidates apply to multiple companies simultaneously. AI engineer pool is meaningful. Best for: companies that want inbound candidate interest rather than active sourcing. Limitation: premium subscription cost. 5. Cord. UK-focused tech talent marketplace. AI and ML engineers well-represented. Direct messaging model reduces recruiter overhead. Best for: UK startups wanting direct access to candidates without recruiter intermediaries. Limitation: smaller pool than LinkedIn. 6. Arc.dev. Remote-first AI engineer marketplace. Thoroughly vetted candidates. Good AI engineering depth. Best for: companies comfortable with fully remote engineers and wanting a fast shortlist. Limitation: platform fee structure adds cost above direct hiring. 7. Toptal (engineering track). High-quality vetted AI engineer network. Accepts only a small percentage of applicants. Best for: companies that need a single senior AI engineer quickly and are willing to pay a premium for confidence in quality. Limitation: day rates are among the highest on this list. 8. AI Jobs (specialist boards). Several specialist AI job boards have emerged (AI Jobs, Jobsin.co.uk AI section). Best for: targeted AI engineering postings where you want candidates actively looking in the AI space. Limitation: smaller active candidate pools than general platforms. 9. Specialist AI recruiters (e.g. SODA, Talent Works). Boutique recruiters specialising in AI and machine learning talent. They have networks that do not appear on job boards. Best for: companies that need a recruiter relationship for ongoing or senior hiring. Limitation: placement fees of 18 to 25% of first-year salary. 10. Hackathons and community events (PyData, MLOps Community, AI Engineer World's Fair). Not a platform but a genuine sourcing strategy. AI engineers who participate in the community are often not on job boards. Best for: companies that want to attract actively contributing community members. Limitation: slow and resource-intensive; not suitable for urgent hiring.
Comparison at a Glance
The UK AI engineering market in 2025 has two distinct layers. Senior AI engineers with 3 or more years of production experience (LLM fine-tuning, RAG system design, ML platform engineering) command salaries of GBP 90,000 to 140,000 or contractor day rates of GBP 550 to 900. Mid-level engineers with 1 to 3 years of applied AI experience command GBP 65,000 to 90,000 or day rates of GBP 400 to 550. Platforms differ in which layer they serve best. Toptal and Turing access the upper tier, with thorough vetting and premium pricing. Otta and Cord serve the mid-level market effectively. LinkedIn spans both but requires more filtering effort. The contractor versus permanent trade-off deserves attention. For companies validating an AI product or building a time-limited sprint team, contractors offer three advantages: speed to start (weeks versus months for permanent hiring), no long-term commitment, and access to senior specialists who prefer contract work. The premium (contractor day rates typically represent 1.4 to 1.8 times the equivalent permanent cost on an annualised basis) is justified for short-term intensive work. For companies building long-term AI capability, permanent engineers build institutional knowledge that contractors do not. The ideal strategy for many early-stage companies is contractor-first for speed, then permanent hire once the product is validated and the right candidate profile is clear. SpeedMVPs often serves as the initial AI build team before a company hires its first permanent AI engineer, providing the working product and code that informs exactly what kind of engineer to hire next.
How to Choose the Right Option for Your Situation
The hiring strategy should follow the company stage and the role's purpose. Three scenarios have different optimal approaches. You need a senior AI engineer hired within 4 to 6 weeks for a permanent role: use LinkedIn for direct outreach combined with one specialist AI recruiter. The recruiter accesses passive candidates who are not actively looking. LinkedIn gives you reach into your extended network. Budget 6 to 10 weeks for this process with these resources. You need an AI engineering contractor to start in 2 to 3 weeks: Toptal or Turing for a thoroughly vetted senior contractor, or Cord and Hired for a faster, slightly less vetted route. Contractors can typically start faster than permanent hires because there is no offer, notice period, or visa process. Budget GBP 500 to 800 per day for a competent senior AI engineering contractor in the UK market. You are not sure what you need to hire for yet: this is more common than founders admit. When the product requirements are not yet clear, hiring a permanent AI engineer is premature. Use an agency like SpeedMVPs to build the MVP, then use the resulting product and codebase to define the engineer you actually need to hire. This sequence is faster and cheaper than hiring before you are ready. AI engineering job requirements: when writing the job spec, be specific about the AI skills you need. "AI experience" is meaningless. "Production experience with RAG pipelines using LlamaIndex or LangChain, familiarity with LLM evaluation frameworks, and experience deploying AI APIs to cloud infrastructure" attracts different (better) candidates.
Our Recommendation
For UK companies needing a senior AI engineer hired quickly, the combination of LinkedIn personalised outreach and one specialist AI recruiter (SODA or Talent Works) is the most reliable approach. Set a realistic timeline of 6 to 10 weeks for a permanent hire at this level. For contractors, Toptal or Turing provide vetted candidates with fast availability. Expect to pay GBP 500 to 800 per day for a senior AI contractor who can contribute immediately. For early-stage companies that are not yet ready to hire but need AI expertise now, working with SpeedMVPs as a delivery partner is a faster and more cost-certain path than hiring. We deliver a complete AI product in 2 to 3 weeks, and the resulting codebase and architecture give you a clear picture of the engineer profile you need to hire to take it forward. Get a free consultation at speedmvps.co.uk