~/portfolio $ whoami
Edwin M. King'ori
Freelance Back-End Engineer & Data Analyst
I'm a freelance back-end engineer and data analyst with a focus on Python-based web services and distributed systems. I enjoy designing systems that are observable, testable, and easy to reason about — from the database schema to the deployment pipeline. I work primarily through Fiverr and direct client engagements.
On the data side, I surface hidden insights in large datasets using Python (pandas), R, and SQL, with a focus on cleaning, exploratory analysis, and visualization. I also leverage AI as an engineering optimization tool — to audit logic for edge cases, validate architectural decisions, and stress-test designs — rather than as a code-generation shortcut.
Skills
Tools & technologies I work with
Languages
- Python
- Go
- SQL
- Bash Scripting
- React.js
Frameworks & Libs
- FastAPI
- Django
- Django REST Framework
- Celery
- SQLAlchemy
- BeautifulSoup4
- Scrapy
- Selenium
Databases & ORMs
- PostgreSQL
- MySQL
- SQLite
- Redis
- Neo4j
- Django ORM
- Alembic
Tools & DevOps
- Docker
- AWS
- GitHub Actions
- Postman
- Linux (Ubuntu)
Data Analysis
- Python (pandas)
- R
- Excel
- ggplot2
- SQL
- Matplotlib
- Seaborn
- Power BI
- Tableau
Engineering w/ AI
- AI-assisted code review
- Logic & edge-case auditing
- Architecture validation
- AI automation tools & agents
Experience
Where I've worked
Back-End Engineer
Mar 2026 – PresentLending Ledger Backend·Freelance Project
FastAPIPostgreSQLRedisDockerSQLAlchemyAlembicTelegram Bot
- ▸Designed an immutable financial ledger architecture enforced at the PostgreSQL layer via BEFORE UPDATE / BEFORE DELETE / BEFORE TRUNCATE triggers — no financial record can be altered or deleted regardless of the issuing role.
- ▸Engineered concurrency-safe disbursement flows using SELECT … FOR UPDATE row locking and end-to-end idempotency with UNIQUE(idempotency_key) + INSERT … ON CONFLICT DO NOTHING.
- ▸Integrated a Telegram Bot as a field-facing operator interface with multi-step conversational flows for borrower registration, loan creation, disbursement, repayment, and balance enquiry.
- ▸Secured the bot with HMAC-signed Redis conversation state, webhook deduplication, secrets.compare_digest token verification, and a user ID whitelist.
Back-End Engineer
Jun 2025 – Feb 2026STORJ API & Diploma Certificates Processing·Freelance Contract — Fiverr
FastAPIMariaDBDockerAWSCeleryRedisWeb3.py
- ▸Built scalable FastAPI endpoints for upload/download/management across multiple Storj buckets, with student diploma data stored in MariaDB.
- ▸Used Python to prefill PDF templates with student data, upload certificates to Storj, and email students downloadable public URLs.
- ▸Integrated Celery and Redis for async email delivery; integrated Web3.py for blockchain-based certificate hash storage for verifiable authenticity.
- ▸Stored sensitive credentials (access grants, MariaDB, auth secrets) in AWS Secrets Manager; containerised the full stack with Docker.
Back-End Engineer
Jul 2025PhonepeAPI Analysis·Freelance Contract — Fiverr
FastAPIPostgreSQLDockerAWSMFAPhonemizer
- ▸Developed a pronunciation analysis API processing audio (PCM / MP3) and text, generating phonemes via Montreal Forced Aligner and Phonemizer.
- ▸Built secure endpoints: retrieve phoneme analysis by ID, analyse pronunciation from audio or text, upload analysed data to the database.
- ▸Implemented automated logging with time-based retention; containerised with Docker; stored credentials in GitHub Actions Secrets.
Project Supervisor
Feb 2025 – May 2025NeuroPayAPI·Freelance Contract — Fiverr
FastAPIRedisPostgreSQLDockerAWSOpen Exchange API
- ▸Supervised and contributed to a payment and transaction API infrastructure, integrating Open Exchange API for real-time currency and exchange-rate data.
- ▸Integrated Redis caching with HMAC-secured keys to prevent key collisions and enumeration attacks, significantly reducing redundant database access.
- ▸Implemented JWT-based authentication, rate limiting, and a "Remember Me" session extension feature; stored credentials in AWS Secrets Manager.
Data Analyst
May 2024 – Oct 2024Program Injury Report Analysis·Freelance Contract — Fiverr
PythonpandasSQLExcel
- ▸Conducted a comprehensive examination of 700,000+ OSHA records using Python (pandas), SQL, and Excel — evaluating injury rates across sites and correlating them with OSHA program participation to assess the programme's efficacy.
- ▸Used pandas for data cleaning and transformation, SQL for efficient querying, and Excel for statistical analysis and visualization — surfacing actionable insights for client business decisions.
Data Analyst
Oct 2024Market DonorData Summary·Freelance Contract — Fiverr
Rggplot2Excel
- ▸Cleaned, validated, and summarized three relational datasets (gifts, promotions, donor records) using R, ensuring consistency and readiness for analysis.
- ▸Conducted exploratory analysis to uncover hidden patterns and correlations, and produced visual analyses with ggplot2 to identify relationships among the three variables.
Data Moderation & Data Entry
Nov 2021 – Jun 2024SAMA (previously SamaSource Kenya)·Full-time · Nairobi, Kenya
Excel
- ▸Re-organised real-time user-generated data for integration into the organisation's workflow; ensured accurate data entry and consistency to support reliable reporting.
- ▸Conducted regular data validation and quality checks to identify errors, duplications, and incomplete records; collaborated with QA and analytics teams to standardise data formats and classification rules.
Testimonials
What clients say
View all reviews on Fiverr ↗@lionking1705
Venezuela
Lending Ledger Project
@webdevite
Norway
PhonemeAPI Analysis
@webdevite
Norway
PhonemeAPI Analysis
@daechong364
Panama
STORJ API
@daechong364
Panama
STORJ API
@jmiller_97
USA
Ecommerce API
@greg_biz
USA
SQLAlchemy Modelling
@calvinvernon
USA
Data Analytics
8 reviews
Contact
Let's work together
Whether you have a project in mind, a question about my work, or just want to connect — my inbox is always open.