00Home
01About Me
02Technologies
03Experience
04Personal Projects

[ OK ] mounted /dev/brain

[ INFO ] loaded modules: java, spring, aws

[ OK ] kernel coffee.service active (running)

Juan Espares

Hi, I'm Juan.

$ |

Backend software engineer based in Brisbane. I work primarily in Java and Spring Boot, building APIs and integrations that quietly do their job.

./see-my-work cat about.md

Years shipping

AWS

SAA Certified

CompSci grad

$ cat ./about.md

01.

About myself

A LITTLE CONTEXT

Hi, I'm Juan. I'm a software engineer based in Brisbane with over 4 years of experience. I studied Computer Science at the University of Queensland after a detour through pharmacy, which is probably why I still gravitate toward health-related work. I picked up my AWS Solutions Architect Associate along the way.

I've worked across healthcare and government sectors, optimising API integrations and automating manual workflows. I enjoy taking something messy or painful and making it quiet and reliable.

Outside of work, you'll find me on the padel courts, tinkering with side projects, or diving into football and health analytics. Feel free to connect, I'd love to chat!

Location: Brisbane, AU
Role: Backend Engineer
Stack: Java · Spring · .NET
Cloud: AWS SAA-C03
Edu: BCompSci, UQ
IRL: Padel · football · health analytics

$ ls -la ./stack/

02.

Technologies

THE STACK

Backend

Java

My daily driver. Spring Boot APIs, the works.

01 / 16

HOVER TO PAUSE · CLICK A CHIP TO FOCUS

$ git log --oneline --graph --since=2016

03.

Experience

THE PATH SO FAR

WORK2024 — Current

Backend Software Engineer

@ Contal Services

Aged-care software for healthcare providers, including integrations with Australian government aged-care systems.

Optimised government API integration with connection pooling and two-tier caching — cut API calls 66–75%, bandwidth 94%, and monthly costs 66%.
Delivered end-to-end Care Management app (React, Java/Spring Boot), automating 2 FTE of manual data entry.
Built Jetstar API integrations for flight booking, fare rules, SSR handling, and bundle search.

WORK2023 — 2024

Junior Software Engineer

@ Dye and Durham

Primarily .NET microservices with Angular frontend deployed through kubernetes in GCP.

Migrated legacy SOAP integration layer to REST via a Java API client, protecting a major revenue stream with zero downtime.
Integrated Keycloak SSO with OAuth 2.0 and self-service password reset, modernising enterprise IAM.
Authored sequence diagrams for legacy integration flows, accelerating team knowledge transfer.

WORK2022 — 2023

Software Developer

@ Scriptsoft

Monolithic .NET framework applications for pharmaceutical and small business software. Worked part time during my uni days before transitioning to full time upon graduation.

Built a custom Power BI solution for pharmacy inventory — real-time stock tracking and automated reconciliation.
Maintained internal systems end-to-end, owning the full dev and deployment lifecycle.

EDU2019 — 2022

Bachelor of Computer Science

@ University of Queensland

Pivoted from pharmacy. Specialised in software engineering.

WORK2017 — 2019

Pharmacy Assistant

@ Chemist Warehouse

Worked in a fast paced environment where time management and communication / customer support skills were vital.

Fast-paced retail. Time management and customer comms muscles.

EDU2016 — 2018

Bachelor of Pharmaceutics and Therapeutic Science

@ University of Queensland

Early grad exit from UQ Pharmacy before switching to CS

EDU2018

Pharmacy Student

@ Calanna Terrywhite

rural pharmacy student placement

medication dispensing

$ systemctl status proj

04.

Personal Projects

A FEATURED BUILD

Featured

Auto-Haaland

A Python-based Fantasy Premier League prediction system. XGBoost trained on SageMaker, a Lambda pipeline crunches fixtures and form into ML features, and an API Gateway endpoint serves the predictions out of DynamoDB. The frontend below is just a view onto it.

PythonXGBoostAWS LambdaSageMakerDynamoDBSAM

see it live · /FPL repo on github

// Edit the code on the right — it's a real, focusable editor. Switch tabs above.

~/projects/auto-haaland

"""
API Handler Lambda

Provides REST API endpoints for querying FPL predictions from DynamoDB.
Uses AWS Lambda Powertools for routing and structured logging.
"""

import os
from decimal import Decimal
from typing import Any

from aws_lambda_powertools import Logger
from aws_lambda_powertools.event_handler import APIGatewayRestResolver, CORSConfig
from boto3.dynamodb.conditions import Key

from common.aws_clients import get_dynamodb_resource

logger = Logger(service="fpl-api")
cors = CORSConfig(allow_origin=os.getenv("CORS_ALLOW_ORIGIN", "*"))
app = APIGatewayRestResolver(cors=cors)

TABLE_NAME = os.getenv("TABLE_NAME", "fpl-predictions")

def _decimal_to_float(obj: Any) -> Any:
    if isinstance(obj, Decimal):
        return float(obj)
    if isinstance(obj, dict):
        return {k: _decimal_to_float(v) for k, v in obj.items()}
    if isinstance(obj, list):
        return [_decimal_to_float(x) for x in obj]
    return obj

@app.get("/top")
def top_predictions():
    gw = int(app.current_event.get_query_string_value("gameweek"))
    position = app.current_event.get_query_string_value("position")
    limit = int(app.current_event.get_query_string_value("limit", "15"))

table = get_dynamodb_resource().Table(TABLE_NAME)
    resp = table.query(
        KeyConditionExpression=Key("gameweek").eq(gw),
        FilterExpression=Key("position").eq(position) if position else None,
    )
    rows = sorted(resp["Items"], key=lambda r: r["haul_probability"], reverse=True)
    return {"predictions": _decimal_to_float(rows[:limit])}

def lambda_handler(event, context):
    return app.resolve(event, context)

● editableUTF-8 · LF · Python