Kristina A.
API Development SME Engineer - Custom Builds & System Integrations
US-Based Principal Engineer | Zero Outsourcing | 25+ Years in the Trenches I provide the technical certainty that only comes from longevity. With over 100 projects completed on Upwork and experience dating back to the earliest days of the web, I build robust backend architecture that works the first time. I Make Systems Talk to Each Other — HubSpot, Jobber, WooCommerce, Mailchimp, Salesforce, FieldAware, Workyard, and more. If your CRM, website, or field-service tools aren't syncing the way they should, that's exactly the problem I solve. Recent Work: • HubSpot & Jobber Sync — a custom Python listener and PHP-based integration automating real-time client sync (Create/Update) and job lifecycle automation via high-performance webhooks, built when Zapier and native integrations weren't cutting it. • Custom WordPress Booking Plugin — full Jobber GraphQL API integration for a service-industry client, including a self-service cancel/reschedule flow, taken from early development through staging acceptance. • Field Service Software Integration — built in Airtable with TypeScript automations, connecting two different field-service management platforms (FieldAware and Workyard) so job and crew data flow between them automatically • Large-Scale Data Pipeline — a Python/PHP deduplication and normalization pipeline for a veteran employment nonprofit, processing 113 files and roughly 79,600 records. • Commercial Product Development — authored and released a WooCommerce/Authorize.net payment gateway plugin (CIM vaulting, auth-only checkout with manual capture, subscription billing, debug logging) with LemonSqueezy license management, plus a Python Gmail API bulk mailer tool. Core Expertise: • Python & FastAPI — modern, asynchronous, strictly typed APIs • API Integration & ETL — REST, GraphQL, and legacy SOAP services • PHP & Backend Systems — custom architecture, Laravel, and database optimization • Data Architecture — custom SQL design and complex JSON transformations Why Work With Me: You are hiring a Subject Matter Expert, not a junior developer. I do not outsource, I do not subcontract, and I do not require hand-holding. I translate business requirements into production-ready code that is documented and resilient.
Earnings and projects
Last 6 months ÷ 6
Last 6 months: $3.8k
Billed in all: $210,255$210k
$764 in the last 6 months
Across 7 contracts
Across 132 contracts
Earnings, last 30 days
Skill rankings: Top 10% in AJAX
Ranked by MRR among everyone on Upwork with the skill.
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- #203AJAX2,006 freelancers · 🇺🇸 #10Top 10%🇺🇸#10 of 69
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- #999jQuery8,973 freelancers · 🇺🇸 #76Top 11%🇺🇸#76 of 547
- #1,233API7,943 freelancers · 🇺🇸 #150Top 16%🇺🇸#150 of 735