Our new developers were able to hit the ground running, we've worked with them for over two years now, and they are truly part of our team.
In-house feel, nearshore
MongoDB Developers
MongoDB sits under a great deal of British SaaS, and most of its production pain traces back to early schema and indexing decisions. We embed senior engineers who design document models, aggregation pipelines and APIs that stay fast as the data grows, working your team's hours as our full-time employees.
- Deep in schema design, indexing and aggregation
- At home in microservices, event-driven systems and content stores
- Sitting inside your backend team through the British working day
Aggregation PipelinesIndexing and PerformanceData MigrationsBackup and ReplicationAPI Integration
Our Service
Pair-programmed vetting on real data problems
Every candidate works through a CTO-led process, a technical assessment, live pairing with a senior engineer on modelling and query tuning, then a cultural fit screen and a psychometric assessment we built for software engineers. AI can draft a pipeline stage these days; we are checking whether the candidate knows if it is the right one.
- Matched for MongoDB alongside Node.js and wider backend work
- Assessed on modelling judgement, not memorised operators
- Employment, onboarding and retention stay on our side
Employment and retention stay with us
Where our MongoDB engineers add depth
- Design scalable, flexible document schemas.
- Aggregation PipelinesBuild efficient multi-stage transformations.

- Indexing and PerformanceOptimise indexes and slow-running queries.

- Data MigrationsPlan and execute safe schema migrations.
- Backup and ReplicationConfigure replicasets for reliability.
- API IntegrationConnect MongoDB layers to REST or GraphQL APIs.
The alternative
Get speed, fit and in-house feel without the hiring grind.
Solid lime = yes · outline lime = partial · grey dash = no
Vetting
You see two people - not 200 CVs.
Engineers vet engineers
A senior engineer runs a live technical conversation on the candidate's real stack, not a recruiter working from a keyword list.
Live coding, not take-homes
Real problems solved in front of an assessor, with anti-cheating checks. You see how they actually work, not what they submitted overnight.
A full profile, not a CV
Every candidate arrives with a CV, interview summary, coding-test breakdown and rate in pounds. You decide on evidence.
Every tab is a stage a candidate has to clear. Six of them, all run by our own internal engineers at Cloud Employee, before you see a name.
- Overview
- CV
- Tech interview
- Coding test
- Psychometric
- Soft skills
Scored by people. We use AI to cross-check our own consistency - never to decide who reaches your shortlist.
✓Luka M.
VettedSenior Software Engineer · TypeScript · Python · Cloud · 6 yrs · Zagreb, Croatia (GMT+1)
Assessment
Six years in production Python, the last three on LLM systems - retrieval pipelines, eval suites, and agent tooling for UK fintech. Owns delivery end to end.
AI in practiceShips with Copilot and Claude Code daily, and rewrote 40% of the generated code in his observed task - the judgement is his, the tooling only makes him faster.
Career history
Senior AI Engineer
UK payments platform · 40-person product team
Built the retrieval assistant now resolving 30% of tier-1 tickets; owns its eval suite and guardrails.
Backend Engineer, Python
Travel booking SaaS · Zagreb
Moved fraud scoring onto a real-time feature pipeline; cut false declines by 18%.
Data Engineer
Agency · Python, Postgres, AWS
- Python
- FastAPI
- LangGraph
- pgvector
- Evals & tracing
- AWS
- Docker
Technical interview
Assessed by Marco R., Principal Engineer
12 Jun 2026
55 min · live call
"Walked me through an assistant that was quietly hallucinating refund policy, how he caught it in evals, and what he got wrong on the first fix. Hire-ready for a senior seat."
Live coding test
Repair a leaking retrieval pipeline
88
score
retrieval.py · submitted diff
- hits = index.query(q, k=50)+ hits = index.query(rewrite(q), k=50, filter=tenant)+ hits = rerank(hits, q)[:8] # recall 0.62 -> 0.91+ assert_context_budget(hits, max_tokens=6000)
Psychometric · technical thinking
How he reasons under a real deadline - not a personality quiz.
Top 9%of engineers
we test
A 45-minute reasoning test, scored against the 4,000+ engineers we have already placed. Our assessors do the marking - AI only flags where our own scoring looks inconsistent.
Soft skills · working with your team
"He raised the payment edge case nobody else had spotted, in writing, two days before release."
This is what you receive - not a CV.
Ask our AI anythingWhy Cloud Employee?
Senior data engineering the budget can carry
You get one monthly fee, 50 to 75% below the fully loaded cost of a comparable British hire, on a rolling contract with 30 days notice. A UK-based client success manager stays close, a 1,000 pound annual learning budget keeps skills current, and 97% of our engineers stay beyond two years.
- Reports into your backend lead like any teammate
- HR, compliance and admin carried entirely by us
- Two-week money-back guarantee plus free replacement

Fully supported
We handle the rest so your engineers can focus on building.
Performance reviews
Payroll & compliance
Equipment
Workspace
In-house, without the friction
No upfront fees. No lock-in contracts.
- No placement or upfront fees
- Rolling 30-day contract, cancel anytime
- One monthly rate, everything included
Ready to find your engineer?
Tell us exactly who you need.
In 90 seconds
Two matched engineers in 7 days. No fees, no obligation.
What role are you hiring for?
Pick one to start - you'll see matching engineers at the end.
- 300+ teams built
- 97% stay 2+ years
- Replace if it isn't working
Got questions?
The questions CTOs and founders ask.
Typically 50 to 75% less than a comparable British hire once salary, employer national insurance, pension, recruitment fees and overheads are counted. We do place UK-based MongoDB developers. Most clients choose Eastern Europe, the Philippines or Latin America, where quality matches and cost is lower, and Eastern Europe suits a British working day. The aim is the strongest quality-to-cost ratio we can find, strong database engineers at a sustainable price. Senior MongoDB experience in Britain sits mostly in well-funded scale-ups, which sets the local benchmark. A UK-based client success manager stays your point of contact.
MongoDB is a document database that stores data as flexible JSON-like documents instead of rows and tables, built to scale horizontally. Teams choose it when their data is naturally document-shaped, a product catalogue or a user profile, and when schemas need to evolve without migration ceremonies. Documents map cleanly onto application objects, and the aggregation pipeline handles serious queries inside the database. The flexibility has real costs, without discipline a schemaless store becomes a junk drawer, and heavily relational workloads fit worse than they would in Postgres.
Schema design is the paradox and the priority, because MongoDB does not force a schema, and that makes designing one more important, not less. Look for developers who model documents around access patterns, embedding what is read together and referencing what is not. Indexing literacy matters too, since most performance disasters are missing indexes, and a wrong shard key at scale is among the costliest mistakes in the ecosystem. AI assistants write passable queries and pipelines now, so an engineer who reviews a generated aggregation for index use beats one who merely produces it.
Assess a MongoDB developer through a modelling conversation, because schema design against access patterns is the skill everything else depends on. Describe a real feature and ask them to design the documents, then change the requirements and watch the redesign, since embedding versus referencing under shifting patterns is where understanding shows. Have them read an explain plan and diagnose a slow query, a short and brutally revealing exercise. Include AI in the session, watching whether they interrogate the generated pipeline's index behaviour or just admire its syntax. And ask when they would choose Postgres instead.
MongoDB developers remain solidly in demand, because the database sits inside an enormous number of production systems and someone has to run them well. It is one of the most widely deployed databases in production use, so the skills travel and the market for them is liquid. Vector search support has given it a role in AI products, with teams adding semantic retrieval to data they already hold rather than bolting on a separate store. As a foundation it is a reasonable bet where document data dominates, though relational workloads still belong in relational databases.
Yes, our developers use AI assistants for MongoDB work, and the soundness discipline centres on the database's specific failure modes, which generated code walks into readily. Assistants produce queries and pipelines that are syntactically fine and operationally naive, no thought for indexes or memory limits, so engineers review generated database code against explain plans before it ships. These verification habits are assessed during vetting, in live pairing with a senior engineer, and we test whether candidates use AI tooling well. Internally the same rule holds, AI accelerates screening and matching, humans make the decisions.
MongoDB developers pass our four-stage, CTO-led vetting, judged by engineers who have run production databases rather than recruiters pattern-matching CVs. The stages are a technical assessment, live pairing with a senior engineer, a cultural fit screen and a psychometric assessment for software engineers. Pairing leans on data modelling and query diagnosis, and includes watching candidates verify what their AI tools generate. Matched candidates interview within 7 working days, are embedded in about two weeks, and are covered by a two-week money-back guarantee and free replacement. 97% of the engineers we embed stay beyond two years.
You are typically interviewing matched candidates within 7 working days of a requirements call, and developers are often embedded and pushing code within about two weeks. From there it is a rolling monthly contract with 30 days' notice, one monthly fee, and no placement charges. You can scale up or down as the work changes, and you pay nothing to interview.
There is a two-week money-back guarantee, and if you want to continue we replace the developer free of charge. In practice this rarely comes up, because you interview a shortlist of two candidates who have already passed a CTO-led technical assessment and a live pair programming session, so the fit question is largely settled before anyone starts.
Proof, not promises
Hear from our customers
In their words













