You will get AI/RAG integration built into your Java or Python backend
Top Rated
Project details
I integrate AI and RAG into your existing Java or Python backend without rewriting what ships in production. Spring Boot with Spring AI on the Java side, FastAPI with LangChain on the Python side, grafted onto your stack.
Credentials that cut hiring risk: Toptal Top 3%, 3,600+ Upwork hours, 100% Job Success, ex-Infosys Specialist Programmer working on Apple, BP, and Vodafone. I've shipped a payment system at $50M+ USD with 99.99% accuracy, a HealthTech platform for 10,000+ Canadian residents (HIPAA-aware), and Fortune 500 retail backends with millions of SKUs.
• What gets built: one new /rag endpoint on your Spring Boot or FastAPI backend, a document ingestion job, a vector database (Pinecone, pgvector, Weaviate), hybrid retrieval (vector plus keyword), LLM integration (OpenAI, Anthropic, or self-hosted Llama 3 for SOC2, HIPAA, GDPR cases), prompt management, token cost tracking, and an admin view. Your team keeps shipping everything else.
3-hour overlap with US Eastern, full overlap with UK and EU. 24-hour reply.
• Tiers: $1,500 Discovery with architecture doc, $5,000 MVP in 3 weeks, $12,000 Production in 6 weeks with CI/CD, monitoring, load tests, and AWS deploy.
Credentials that cut hiring risk: Toptal Top 3%, 3,600+ Upwork hours, 100% Job Success, ex-Infosys Specialist Programmer working on Apple, BP, and Vodafone. I've shipped a payment system at $50M+ USD with 99.99% accuracy, a HealthTech platform for 10,000+ Canadian residents (HIPAA-aware), and Fortune 500 retail backends with millions of SKUs.
• What gets built: one new /rag endpoint on your Spring Boot or FastAPI backend, a document ingestion job, a vector database (Pinecone, pgvector, Weaviate), hybrid retrieval (vector plus keyword), LLM integration (OpenAI, Anthropic, or self-hosted Llama 3 for SOC2, HIPAA, GDPR cases), prompt management, token cost tracking, and an admin view. Your team keeps shipping everything else.
3-hour overlap with US Eastern, full overlap with UK and EU. 24-hour reply.
• Tiers: $1,500 Discovery with architecture doc, $5,000 MVP in 3 weeks, $12,000 Production in 6 weeks with CI/CD, monitoring, load tests, and AWS deploy.
AI Development Type
Deep Learning, Knowledge Representation, Model TuningAI Tools
Amazon SageMaker, Azure Machine Learning, deeplearn.js, Deeplearning4j, Keras, MLflow, PyBrain, PyTorch, TensorFlowAI Development Language
JavaWhat's included
| Service Tiers |
Starter
$1,500
|
Standard
$5,000
|
Advanced
$12,000
|
|---|---|---|---|
| Delivery Time | 7 days | 21 days | 42 days |
Number of Revisions | 2 | 3 | 5 |
AI Model Integration | - | ||
Detailed Code Comments | - | - | |
Knowledge Graph | - | - | - |
Model Documentation | |||
Ontology | - | - | - |
Source Code | - | ||
Taxonomy | - | - | - |
Optional add-ons
You can add these on the next page.
Additional Integration (extra data source)
(+ 3 Days)
+$750
6 reviews
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TA
Thomas A.
Mar 6, 2026
Full Stack Java Developer (Spring Boot 3) Needed for Long-Term Project
NL
Noah L.
Jan 9, 2026
Senior Python/Data Architect needed (FastAPI + dbt) - Manual Coding Mastery Required
YB
Yan B.
Dec 16, 2025
Backend Stripe Connect
WH
Walter H.
Aug 5, 2024
Junior Java Developer
Gopal is very competent and professional Spring Boot developer. He separated microservices for our back-end app modules (Java, Spring Boot) from monolith architecture and worked on extension of those modules. Excellent team player along with ability to work independently or without much help from other team members. Good communication skills.
I recommend Gopal for anyone who's looking for Java Spring Boot Microservices Developer.
I recommend Gopal for anyone who's looking for Java Spring Boot Microservices Developer.
MM
Mitchal M.
Apr 18, 2024
Additional extension to existing framework
It has been my pleasure to work with Gopal for almost two years, and I can vouch for his unmatched proficiency in a broad range of technology. Gopal showed a thorough comprehension of the project needs right away and continuously produced excellent work.
Principal Advantage: Gopal is a very talented developer with expertise in a wide range of technologies, including Java and Spring Boot. His capacity to take on challenging problems in a variety of fields and come up with tasteful answers is really amazing. Not only has he met my expectations, but he has consistently exceeded them.
Problem Solving: Gopal does exceptionally well when faced with challenging tasks. His innovative approach to problem-solving and his practical manner have been quite helpful in getting past roadblocks pertaining to RPA, Websockets, OCR reading, Spring Security, Spring Data MongoDB, and API integration—all crucial elements of the project.
Creative Solutions: Gopal's capacity to think outside the box is what really makes him stand out. His creative ideas have greatly improved the product, making it more effective, scalable, and intuitive. Every piece of code that Gopal creates, whether it is for optimizing MongoDB queries or creating real-time communication via Websockets, demonstrates his dedication to innovation.
Impact: Gopal's contributions have resulted in a significant advancement of the product. I've seen increased customer happiness, lower maintenance costs, and better performance. His knowledge of the whole tech stack is impressive, and I look forward to working with Gopal on more projects in the future.
In conclusion, Gopal is a strategic partner with a wide range of technological competence, not just a service provider. Look no farther if you're looking for the best in Java, Spring Boot, and beyond. I would heartily suggest Gopal to any potential customer.
Principal Advantage: Gopal is a very talented developer with expertise in a wide range of technologies, including Java and Spring Boot. His capacity to take on challenging problems in a variety of fields and come up with tasteful answers is really amazing. Not only has he met my expectations, but he has consistently exceeded them.
Problem Solving: Gopal does exceptionally well when faced with challenging tasks. His innovative approach to problem-solving and his practical manner have been quite helpful in getting past roadblocks pertaining to RPA, Websockets, OCR reading, Spring Security, Spring Data MongoDB, and API integration—all crucial elements of the project.
Creative Solutions: Gopal's capacity to think outside the box is what really makes him stand out. His creative ideas have greatly improved the product, making it more effective, scalable, and intuitive. Every piece of code that Gopal creates, whether it is for optimizing MongoDB queries or creating real-time communication via Websockets, demonstrates his dedication to innovation.
Impact: Gopal's contributions have resulted in a significant advancement of the product. I've seen increased customer happiness, lower maintenance costs, and better performance. His knowledge of the whole tech stack is impressive, and I look forward to working with Gopal on more projects in the future.
In conclusion, Gopal is a strategic partner with a wide range of technological competence, not just a service provider. Look no farther if you're looking for the best in Java, Spring Boot, and beyond. I would heartily suggest Gopal to any potential customer.
About Gopal
Senior Backend Engineer | Java, Spring Boot, Python & AI Integration
100%
Job Success
Surat, India - 4:53 am local time
Senior backend engineer (Java, Spring Boot, Python) with AI built in. 4,100+ hours, $100K+ earned, 100% Job Success, and enterprise delivery for Apple, Fortune 50 food and beverage mncs, Vodafone, and Walmart.
👋 𝐇𝐢, 𝐈'𝐦 𝐆𝐨𝐩𝐚𝐥 𝐒𝐚𝐛𝐡𝐚𝐝𝐢𝐲𝐚.
I've spent 13+ years in software engineering, and I've become the engineer teams trust when the backend simply cannot fail. I'm Expert-Vetted on Upwork (top 1%), Top 3% on Toptal, and a former Specialist Programmer at Infosys (their top 1%), where I built for Apple, British Petroleum, Vodafone UK, and Walmart. Right now I'm Tech Lead on a 500,000-user platform at US Pharmacopeia and a sustaining engineer on Fortune 50 food and beverage mnc's GenAI ordering system through Toptal.
What that means for you: you're not handing your product to someone learning on your budget. You're getting an engineer who has already shipped the hard version of what you're trying to build.
⚙️ 𝗪𝗛𝗔𝗧 𝗜 𝗕𝗨𝗜𝗟𝗗
🔹 AI-integrated backends. RAG, LLM and agent workflows, vector search, wired into real Java or Python systems with Spring AI, LangChain, and the OpenAI and Anthropic APIs. Production, not demos.
🔹 Microservices that scale. Java 17/21 and Spring Boot, brittle monoliths broken into services that hold up under load. (Recently: a Java 8 to 25 migration with zero downtime.)
🔹 SaaS and FinTech platforms. Multi-tenant, zero-trust auth, payment and ledger logic that reconciles to the cent, audit trails, and the test pipelines that keep regressions out.
🔹 Full-stack when you need it. FastAPI, Flask, React and Next.js on top, so one engineer owns the whole arc from schema to screen.
📊 𝗪𝗛𝗔𝗧 𝗜'𝗩𝗘 𝗦𝗛𝗜𝗣𝗣𝗘𝗗 (𝗔𝗡𝗗 𝗪𝗛𝗔𝗧 𝗜𝗧 𝗥𝗘𝗧𝗨𝗥𝗡𝗘𝗗)
✓ $50M a year moves through a FinTech ledger I built. 99.99% accuracy, reconciles to the cent.
✓ 500,000 users sign in through a zero-trust auth platform I architected at US Pharmacopeia.
✓ 2,500+ venues run on Bar.Stream, where a human-in-the-loop RAG engine I built replaced manual product classification, and 200+ automations replaced manual data entry.
✓ 100% invoice-parsing accuracy from an AI agent I built for MPI, manual reconciliation gone.
✓ 60% faster APIs and zero-downtime modernization for 50,000+ educators on KigaPortal.
✓ 75% more API throughput on Apple's repair backend.
Few engineers can put Apple, Fortune 50 food and beverage mncs, a $50M ledger, and production AI on one page. I can, and I can walk you through the architecture and the numbers behind every one.
🛠️ 𝗦𝗧𝗔𝗖𝗞
Java · Spring Boot / Cloud / Security / AI · Python · FastAPI · Node.js · RAG · LangChain · LLM + vector databases · OpenAI + Anthropic · PostgreSQL · MySQL · MongoDB · Elasticsearch · AWS · GCP · Docker · Kubernetes · CI/CD · microservices · event-driven
🌟 𝗛𝗢𝗪 𝗜 𝗪𝗢𝗥𝗞
You work directly with me. Not an agency, not a rotating team, and not a junior building it while a senior name sits on the invoice. I take your idea from a rough brief to a written spec, then I build it: architecture, code, the hard parts, and the reviews. I've carried year-long builds end to end on my own, so nothing gets lost in a handoff.
I keep it efficient. You get working software and a clear weekly update, not a week full of standups. I'm on a call when it actually matters, and when something is at risk you hear it from me early, before it breaks. You set direction, I run the build.
📩 𝗟𝗘𝗧'𝗦 𝗕𝗨𝗜𝗟𝗗 𝗜𝗧
Send me a short note: what you're building and where it's stuck. Within a day you'll get a straight read back, how I'd approach it, the first risk I'd kill, and the one question I'd want answered before we start. If I'm not the right engineer for it, I'll tell you that too.
Steps for completing your project
After purchasing the project, send requirements so Gopal can start the project.
Delivery time starts when Gopal receives requirements from you.
Gopal works on your project following the steps below.
Revisions may occur after the delivery date.
Kickoff call and repo access
30-minute call to confirm scope and surface risks. You give me access to your codebase and a staging environment. I confirm the architecture plan or flag what needs to change before code ships.