Downloads of apps we shipped
Combined iOS + Android installs across our products.
AI & Automation
LLM Development Services
LLM development services for teams building serious applications on large language models — RAG systems, agents, fine-tuned models, and structured-output pipelines. For startups and technical SMBs that need an LLM app that's reliable, evaluated, and affordable in production, not a fragile prompt held together by hope. We engineer the whole pipeline around the model.
What You Get
A Product You Can Ship
01
Production-grade LLM apps
We build LLM systems engineered for reliability — evaluation harnesses, guardrails, and observability. Not a clever prompt that breaks on the inputs you didn't test.
02
Measured, not vibes
Every LLM build ships with an evaluation suite scoring it against real test cases. You know its accuracy and where it fails before users do.
03
Cost and latency under control
We tune prompts, cache, and tier models so the system stays fast and affordable at scale. LLM token costs don't quietly eat your margins.
§ 03MEASURED OUTCOMES
Results that
speak for themselves.
Seven years of shipping. Every number below comes from real products in-market — no vanity metrics.
Long-term or returning clients
Clients work with us 4+ years or come back for more.
Team with 5+ year tenure
A senior team built on retention, not churn.
In investment attracted
Capital raised by startups using products we built.
FIG. 03 — RESULTS SUMMARY, 2019–2026SOURCE: INTERNAL · AGGREGATED ACROSS 40+ ENGAGEMENTS
Our Approach
How We Build With LLMs
Most LLM prototypes die in production — non-determinism, hallucination, and cost. We engineer for those from the first commit, not as an afterthought.
Evaluation before scale
We build an eval suite of real test cases early and score every change against it. You ship improvements you can prove, not prompt tweaks you hope help.
RAG and grounding over fine-tuning
Most use cases need the model grounded in your data, not retrained. We build retrieval pipelines first and reach for fine-tuning only when it genuinely pays off.
Structured output and guardrails
We constrain the model to validated, structured output and add guardrails against unsafe or off-topic responses. The LLM behaves predictably in your system.
Provider-agnostic architecture
We build behind an abstraction so you can switch between Claude, GPT, Gemini, or open models as price and capability shift. No rewrite when the landscape moves.
Selected Work
Projects We've Shipped
§ REVIEWSCLIENT FEEDBACK
What our Clients Say
Every review is real and verifiable — straight from Clutch, Upwork, and LinkedIn. Nothing cherry-picked.
★★★★★
The quality for price is really high.
Prosperity is always happy to share their knowledge.
★★★★★
It feels like they're part of the team, and they make good decisions without needing a lot of support.
I presented Illia with a problem, he helped me think through of a way to solve the problem and best of all: him and his team were able to actually implement it! He's got great entrepreneurial instincts.
★★★★★
I think what sets them apart is the range of skills they bring to a project, as well as their level of knowledge.
★★★★★
From start to finish, the entire experience was nothing short of exceptional.
The team at Prosperity was super fast to respond to all our queries and requests. Their commitment to quality was evident in their extensive testing, ensuring a smooth and seamless integration of SSO into our apps.
★★★★★
The project was an enjoyable and positive experience.
I like the personal touch they have. They offer good bang for the buck.
★★★★★
When I ask Prosperity to do something that doesn't make sense, they suggest alternatives that work better.
★★★★★
They were honest, direct easy to communicate, had great quality and excellent value.
The build quality was very good overall and bugs were fixed quickly.
★★★★★
I'm really happy I chose to work with Illia to develop a face measurement taking iOS application.
He has been very communicative, got the work done on time, delivered a quality application, and was able to solve some technical challenges related to determining landmark points on ARKit-derived 3D model.
FM
Verified Upwork Client
CLIENT · ARKIT FACIAL MEASUREMENT APP
★★★★★
It was such a pleasure to work with Illia for the development of our App.
He is super experienced and has excellent work ethics. Illia delivered our project on time and never missed any milestones along the way. He is our number 1 developer to go to for any technical knowhow.
CA
Verified Upwork Client
CLIENT · CAMERA APP
★★★★★
Prosperity is an amazing team and provide excellent work.
I am looking forward to working with them again in the future. Total class act and very professional, plus excellent code.
CP
Verified Upwork Client
FOUNDER · CRUISE PLATFORM
★★★★★
Illia was fantastic to work with.
Understood requirements well, worked with me to brainstorm ways to achieve the functionality needed, tested and debugged, and delivered a crash-proof, pixel-perfect iPad application.
iP
Verified Upwork Client
CLIENT · IPAD ART INSTALLATION
★★★★★
Illia has done a really great job.
He's a strong communicator through and delivers high quality work. I can highly recommend him for future work. I will be hiring him again in future!
NA
Verified Upwork Client
CLIENT · NATIVE IOS APP
★★★★★
The team was a great help to us in this project!
The delivery and the workflow were very professional. The team went beyond the scope, they took more responsibility and provided us with the required expertise, although the project was complicated. We are happy to recommend this team!
AR
Verified Upwork Client
CLIENT · NFT APP WITH AR
★★★★★
Fast delivery, high code quality, and ability to communicate with the rest of the team.
PB
Verified Upwork Client
CLIENT · PYTHON BACKEND & REACT NATIVE APP
★★★★★
Illia and his team, delivered and completed the project on time.
They are highly professional, excellent communication skills and the entire project was completed smoothly without any issue along the way. We highly recommend them to anyone and have continued working with them on our ongoing projects and future work.
RF
Verified Upwork Client
CLIENT · REACT FRONTEND
★★★★★
The developer communicated well and delivered high-quality code, we already rehired him again.
RN
Verified Upwork Client
CLIENT · REACT NATIVE APP
★★★★★
Working with Prosperity has been a pleasure.
They will do everything possible make your project perfect.
iA
Verified Upwork Client
CLIENT · IOS APP
★★★★★
Illia helped us with frontend development in Swift.
His excellent technical skills are paired with very good communication skills, made it very easy for us to onboard him onto a running project and complete the work as planned.
SM
Verified Upwork Client
CLIENT · SWIFT MOBILE APP
★★★★★
We're impressed with their transparency and ability to solve very challenging technical problems.
★★★★★
The quality for price is really high.
Prosperity is always happy to share their knowledge.
★★★★★
It feels like they're part of the team, and they make good decisions without needing a lot of support.
I presented Illia with a problem, he helped me think through of a way to solve the problem and best of all: him and his team were able to actually implement it! He's got great entrepreneurial instincts.
★★★★★
I think what sets them apart is the range of skills they bring to a project, as well as their level of knowledge.
★★★★★
From start to finish, the entire experience was nothing short of exceptional.
The team at Prosperity was super fast to respond to all our queries and requests. Their commitment to quality was evident in their extensive testing, ensuring a smooth and seamless integration of SSO into our apps.
★★★★★
The project was an enjoyable and positive experience.
I like the personal touch they have. They offer good bang for the buck.
★★★★★
When I ask Prosperity to do something that doesn't make sense, they suggest alternatives that work better.
★★★★★
They were honest, direct easy to communicate, had great quality and excellent value.
The build quality was very good overall and bugs were fixed quickly.
★★★★★
I'm really happy I chose to work with Illia to develop a face measurement taking iOS application.
He has been very communicative, got the work done on time, delivered a quality application, and was able to solve some technical challenges related to determining landmark points on ARKit-derived 3D model.
FM
Verified Upwork Client
CLIENT · ARKIT FACIAL MEASUREMENT APP
★★★★★
It was such a pleasure to work with Illia for the development of our App.
He is super experienced and has excellent work ethics. Illia delivered our project on time and never missed any milestones along the way. He is our number 1 developer to go to for any technical knowhow.
CA
Verified Upwork Client
CLIENT · CAMERA APP
★★★★★
Prosperity is an amazing team and provide excellent work.
I am looking forward to working with them again in the future. Total class act and very professional, plus excellent code.
CP
Verified Upwork Client
FOUNDER · CRUISE PLATFORM
★★★★★
Illia was fantastic to work with.
Understood requirements well, worked with me to brainstorm ways to achieve the functionality needed, tested and debugged, and delivered a crash-proof, pixel-perfect iPad application.
iP
Verified Upwork Client
CLIENT · IPAD ART INSTALLATION
★★★★★
Illia has done a really great job.
He's a strong communicator through and delivers high quality work. I can highly recommend him for future work. I will be hiring him again in future!
NA
Verified Upwork Client
CLIENT · NATIVE IOS APP
★★★★★
The team was a great help to us in this project!
The delivery and the workflow were very professional. The team went beyond the scope, they took more responsibility and provided us with the required expertise, although the project was complicated. We are happy to recommend this team!
AR
Verified Upwork Client
CLIENT · NFT APP WITH AR
★★★★★
Fast delivery, high code quality, and ability to communicate with the rest of the team.
PB
Verified Upwork Client
CLIENT · PYTHON BACKEND & REACT NATIVE APP
★★★★★
Illia and his team, delivered and completed the project on time.
They are highly professional, excellent communication skills and the entire project was completed smoothly without any issue along the way. We highly recommend them to anyone and have continued working with them on our ongoing projects and future work.
RF
Verified Upwork Client
CLIENT · REACT FRONTEND
★★★★★
The developer communicated well and delivered high-quality code, we already rehired him again.
RN
Verified Upwork Client
CLIENT · REACT NATIVE APP
★★★★★
Working with Prosperity has been a pleasure.
They will do everything possible make your project perfect.
iA
Verified Upwork Client
CLIENT · IOS APP
★★★★★
Illia helped us with frontend development in Swift.
His excellent technical skills are paired with very good communication skills, made it very easy for us to onboard him onto a running project and complete the work as planned.
SM
Verified Upwork Client
CLIENT · SWIFT MOBILE APP
★★★★★
We're impressed with their transparency and ability to solve very challenging technical problems.
● HOVER TO PAUSEREAD ALL REVIEWS ON CLUTCH →
Mobile Apps Across Every Vertical
Deep domain knowledge across core verticals — so you get a team that understands your market, not just your code.
How It Works
From Prompt Prototype to Production LLM System
01
Use Case & Eval Design
We define the task, success criteria, and build an evaluation set from real data. You get a measurable target before any build starts.
02
Pipeline Prototype
We build the core LLM pipeline — retrieval, prompting, or agent logic — and score it against the evals. You get proof it meets the bar on real cases.
03
Production Engineering
We add guardrails, structured output, caching, fallbacks, and observability. You get an LLM system that survives real traffic and edge cases.
04
Deploy & Monitor
We ship with dashboards for quality, latency, and cost. You get ongoing visibility and a feedback loop to keep improving the model's output.
01
Use Case & Eval Design
We define the task, success criteria, and build an evaluation set from real data. You get a measurable target before any build starts.
02
Pipeline Prototype
We build the core LLM pipeline — retrieval, prompting, or agent logic — and score it against the evals. You get proof it meets the bar on real cases.
03
Production Engineering
We add guardrails, structured output, caching, fallbacks, and observability. You get an LLM system that survives real traffic and edge cases.
04
Deploy & Monitor
We ship with dashboards for quality, latency, and cost. You get ongoing visibility and a feedback loop to keep improving the model's output.
Why Prosperity
Why Technical Teams Choose Us for LLM Development
Anyone can wire up a prompt. Building an LLM system that's reliable, evaluated, and affordable in production is engineering — and that's our work.
Production LLM experience
We've shipped LLM features into apps with thousands of daily users. We know the failure modes — hallucination, drift, cost spikes — and how to engineer against them.
Evaluation as a first-class concern
We treat evals like tests. Every change is scored, so quality is measurable and regressions get caught before they reach users.
Honest about fine-tuning
Fine-tuning is often unnecessary and expensive. We'll tell you when prompting and RAG solve your problem cheaper, even though it means a smaller project for us.
Non-determinism is real
LLMs won't give identical answers every time, and no amount of engineering removes that fully. We design systems that tolerate it rather than pretend it away.
FAQ
Frequently Asked Questions
We build applications on large language models — RAG systems that ground answers in your data, agents that take actions across tools, structured-output pipelines, and fine-tuned models where justified. The work includes prompt engineering, retrieval, evaluation harnesses, guardrails, cost control, and production deployment. The goal is an LLM system reliable enough to run unattended, not a fragile prototype.
§ 13 — Contact
Book a call.
Leave with a plan.
A direct line to the engineers who'll actually do the work. We'll map your problem to a scope and timeline in one short conversation.
Trusted & verified
Clutch★★★★★5.0 · 12 reviews
AgencyReviewVerified · Software AgenciesOr emailinfo@theprosperity.team