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Hann .

Projects and case studies

Public code and production work, shown in motion

Type
Cloud
Area 12
16 provider aliases, one assume_roleus-west-2us-west-1us-east-2us-east-1sa-east-1ap-south-1ap-southeast-1ap-southeast-2ap-northeast-3ap-northeast-2ap-northeast-1eu-north-1eu-west-1eu-west-2eu-west-3eu-central-1assume_roleSame role_arn in every region16 regions · 24 modules · one locals map per region

PF-01 · AWS · IaC

AWS multi-region Terraform

A Terraform module set that builds the same infrastructure in 16 AWS regions from one locals map per region.

Role
Design and implementation
Period
Personal project · released Nov 2026
Cloud
AWS
Scale
16 regions · 24 modules · 3 examples
Key tech
Terraform · AWS · EKS · CloudWatch

Case study

GKE node pool SURGE upgrademax_surge = 5 max_unavailable = 0New nodesOld nodesOld nodes leave one at a time · 0 unavailableSwapped to 5 new nodes · 0 nodes unavailableSoak 3600s applies only to BLUE_GREEN

PF-02 · GCP · IaC

GCP Terraform GKE platform

A module set that keeps capacity during GKE node pool upgrades with SURGE, and opens only what a VPN needs through a firewall baseline, all as code.

Role
Design and implementation
Period
Personal project · released Nov 2026
Cloud
GCP
Scale
22 modules · 3 examples
Key tech
Terraform · GCP · GKE · Cloud Logging

Case study

CloudAudit tracks into a COS bucketCOS bucketCAMCVMCBSVPCcam/cvm/disk/vpc/AddUserCreateApiKeyAttachUserPolicyRunInstancesTerminateInstancesResizeDiskCreateSecurityGroupPolicies4 audit tracks · one COS prefix per serviceRed border: risky event

PF-03 · Tencent · IaC

Tencent Cloud audit-ready Terraform

Tencent Cloud modules that define CloudAudit tracks per service, so risky changes land in a COS bucket.

Role
Design and implementation
Period
Personal project · released Nov 2026
Cloud
Tencent
Scale
18 modules · 3 examples
Key tech
Terraform · Tencent Cloud · CloudAudit · COS

Case study

iam_custom_policyiam_useriam_custom_roleiam_groupvpcelastic_ipebsinternet_gatewaysecurity_groupvpc_endpointvpc_peeringelasticache_subnet_groupnat_gatewayroute_tableinstance_profileec2_instance

PF-04 · AWS · Terragrunt

AWS Terragrunt DRY IaC

Sixteen Terraform modules behind one root config, with Terragrunt running them in order from their dependency graph.

Role
Design and implementation
Period
Personal project · released Nov 2026
Cloud
AWS
Scale
16 modules · 16 units · 4 dependency levels
Key tech
Terragrunt · Terraform · AWS

Case study

AWSGCPTencentCross-account roleiamfirewallinstanceloadbalancervpcaudit_logunusedCommon schemaGoogle SheetsSlackTelegramImmediate alerts on critical eventsMonthly archive

PF-05 · Multi-cloud · Python

Multi-cloud asset and audit automation

A Python tool that collects assets, permissions, and audit logs from AWS, GCP, and Tencent Cloud into one schema, and alerts on risky events.

Role
Design and implementation
Period
Personal project · released Nov 2026
Cloud
AWS · GCP · Tencent
Scale
3 clouds · 7 collectors · 49 audit actions
Key tech
Python · boto3 · Google Cloud SDK · Tencent Cloud SDK

Case study

CEOUser directiveManagementTechnologySalesEmmaChief of staffMiaFinanceAvaHRSophiaTech leadNoahSenior engineerLunaEngineerEthanDB engineerLiamQA engineerChloeSecurity engineerJamesPlanning and salesleadOliviaContent marketer(off by default)Model priority · estimated cost recordedSimulated: assignment, model selection, and cost tracking onlyNo language model API is called

PF-06 · AI · FastAPI

AetherCrew: a virtual company of 11 AI employees

A hand-built orchestrator that assigns work, picks models, and tracks cost for 11 AI employees in a virtual company. Agent work is simulated and no language model API is called.

Role
Design and implementation
Period
Personal project · released Nov 2026
Cloud
None
Scale
11 AI employees · 3 divisions · 8 dashboard pages
Key tech
Python · FastAPI · WebSocket · pytest

Case study

Firewall requestSource · Destination · Portnetops confirmnetops modifynetops flowlogIs it already open?Preview only the blocked flowsVerify with real trafficOpenNo work neededBlockedOn to the next stepPreviewPrints affected resources andrules--apply + typed applyAdds rules onlyTraffic foundCloudWatch Logs · AthenaNothing changes by default

PF-09 · AWS · Python

AWS firewall request automation

A CLI that checks whether a firewall request is already open, previews changes only for what is blocked, and verifies the real traffic.

Role
Design and implementation
Period
Personal project · released Nov 2026
Cloud
AWS
Scale
3-step CLI · 4 input formats · 4 resource types
Key tech
Python · boto3 · AWS · CloudWatch Logs

Case study

DMZPrivateInternetShieldStandardCloudFront /WAFFilters webattacksALBDMZ subnetNetworkFirewallFirewall on theVPC pathVPC workloadsNo public IPOutbound: allowed targets onlyOne set of Terraform codeApplied the same way across multiple AWS accounts

Woori FIS · AWS · Security

Woori Financial Group AWS security architecture

Moved network separation requirements across multiple AWS accounts into subnet and firewall structure, and standardized security settings as one set of Terraform code.

Role
Cloud Security Engineer · Network Security team, Information Security
Period
Feb 2026 – Oct 2026
Cloud
AWS
Scale
Multiple AWS accounts
Key tech
Terraform · AWS Network Firewall · AWS WAF · AWS Shield Standard

Case study

1. Firewall firstNetwork and firewall rulesmatch GCP2. Online MigrationServers move with themigration tool3. Private validationSame infrastructure, checkedwith the dev team4. Phased trafficcutoverTraffic moves in stages aftervalidationGCPTencent Cloud80 servers · 20 databasesPrivate runLIVEAbout 1 week · 0 downtime · gcp.tf to tencentcloud.tf

Com2us Platform · Migration

Zero-downtime migration from GCP to Tencent Cloud

Moved 80 servers and 20 databases of Summoners War: Chronicles from GCP to Tencent Cloud in about one week with no downtime.

Role
Cloud Engineer · Main engineer
Period
Feb 2023 – Feb 2026
Cloud
GCP · Tencent
Scale
80 servers · 20 databases
Key tech
Terraform · GCP · Tencent Cloud · Online Migration

Case study

GCPTencent Cloud600 servers · 70 databases (across both clouds)WebGameDBAdmin

Com2us Platform · Multi-cloud

Summoners War: Sky Arena multi-cloud and firewall redesign

A massive game platform across GCP and Tencent Cloud, with 600 servers and 70 databases, a full firewall policy redesign, and patching with no maintenance window.

Role
Cloud Engineer · Main engineer
Period
Feb 2023 – Feb 2026
Cloud
GCP · Tencent
Scale
600 servers · 70 databases · Massive
Key tech
GCP · Tencent Cloud · Terraform · Terragrunt

Case study

3,500 servers · 650 databasesDedicated Host ASeparate fault zonesDedicated Host BSeparate fault zonesDedicated Host CSeparate fault zonesMain engineer

C&Thoth · Azure MSP

MIR4 Global: massive Azure infrastructure and automated DDoS blocking

Dedicated operation of a global game with 3,500 servers and 650 databases on Azure, plus a pipeline that finds DDoS sources in logs and adds them to an NSG automatically.

Role
Cloud Engineer · Main engineer (client: WEMADE)
Period
Jul 2021 – Feb 2023
Cloud
Azure
Scale
3,500 servers · 650 databases · Massive
Key tech
Azure · Dedicated Host · PowerShell · Log Analytics

Case study

TimeRevenueInfrastructure costRevenue and cost monitored togetherUnused resources flaggedUp to -62%

Com2us Platform · FinOps

Dragon Sky FinOps: 62% lower infrastructure cost

Linked revenue metrics with infrastructure cost and found unused resources automatically every day with Python, cutting infrastructure cost by up to 62%.

Role
Cloud Engineer · Main engineer
Period
Feb 2023 – Feb 2026
Cloud
Azure
Scale
10 servers · 5 databases
Key tech
Azure · Python · Billing monitoring

Case study

Open to work · Cloud infrastructure and security